File headers: use SPDX license identifiers

Some files needed to be changed manually.

204 files changed, 604 insertions, 1427 deletions

diff --git a/add_curve_extra_objects/add_curve_braid.py b/add_curve_extra_objects/add_curve_braid.py
index ba32b563..32e8894c 100644
--- a/add_curve_extra_objects/add_curve_braid.py
+++ b/add_curve_extra_objects/add_curve_braid.py
@@ -1,4 +1,4 @@
-# gpl: author Jared Forsyth <github.com/jaredly>
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 """
 bl_info = {
diff --git a/add_curve_extra_objects/add_curve_celtic_links.py b/add_curve_extra_objects/add_curve_celtic_links.py
index 663f8b7e..d6b777de 100644
--- a/add_curve_extra_objects/add_curve_celtic_links.py
+++ b/add_curve_extra_objects/add_curve_celtic_links.py
@@ -1,26 +1,7 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2013 Adam Newgas
+
 # Blender plugin for generating celtic knot curves from 3d meshes
-#
-# The MIT License (MIT)
-#
-# Copyright (c) 2013 Adam Newgas
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
 
 bl_info = {
     "name": "Celtic Knot",
diff --git a/add_curve_extra_objects/add_curve_curly.py b/add_curve_extra_objects/add_curve_curly.py
index d49cb8fb..0111aaf6 100644
--- a/add_curve_extra_objects/add_curve_curly.py
+++ b/add_curve_extra_objects/add_curve_curly.py
@@ -1,4 +1,4 @@
-# gpl: author Cmomoney
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 # DevBo Task https://developer.blender.org/T37299
 
diff --git a/add_curve_extra_objects/add_curve_spirals.py b/add_curve_extra_objects/add_curve_spirals.py
index f3c5a074..25a217a7 100644
--- a/add_curve_extra_objects/add_curve_spirals.py
+++ b/add_curve_extra_objects/add_curve_spirals.py
@@ -1,4 +1,4 @@
-# gpl: author Alejandro Omar Chocano Vasquez
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 """
 bl_info = {
diff --git a/add_curve_sapling/presets/callistemon.py b/add_curve_sapling/presets/callistemon.py
index 7b0ea8e3..cfd1a742 100644
--- a/add_curve_sapling/presets/callistemon.py
+++ b/add_curve_sapling/presets/callistemon.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'handleType': '0', 'rotate': (99.5, 137.5, 137.5, 137.5), 'baseSize_s': 0.1600000560283661, 'af2': 1.0, 'pruneRatio': 0.75, 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'pruneWidthPeak': 0.5, 'boneStep': (1, 1, 1, 1), 'nrings': 0, 'leafScale': 0.4000000059604645, 'makeMesh': False, 'baseSize': 0.30000001192092896, 'lengthV': (0.0, 0.10000000149011612, 0.0, 0.0), 'shapeS': '10', 'pruneBase': 0.11999999731779099, 'af3': 4.0, 'loopFrames': 0, 'horzLeaves': True, 'curveRes': (8, 5, 3, 1), 'minRadius': 0.001500000013038516, 'leafDist': '6', 'rotateV': (15.0, 0.0, 0.0, 0.0), 'bevel': True, 'curveBack': (0.0, 0.0, 0.0, 0.0), 'leafScaleV': 0.15000000596046448, 'prunePowerHigh': 0.5, 'rootFlare': 1.0, 'prune': False, 'branches': (0, 55, 10, 1), 'taperCrown': 0.5, 'useArm': False, 'splitBias': 0.5499999523162842, 'segSplits': (0.10000000149011612, 0.5, 0.20000000298023224, 0.0), 'resU': 4, 'useParentAngle': True, 'ratio': 0.014999999664723873, 'taper': (1.0, 1.0, 1.0, 1.0), 'length': (0.800000011920929, 0.6000000238418579, 0.5, 0.10000000149011612), 'scale0': 1.0, 'scaleV': 2.0, 'leafRotate': 137.5, 'shape': '7', 'scaleV0': 0.10000000149011612, 'leaves': 150, 'scale': 5.0, 'leafShape': 'hex', 'prunePowerLow': 0.0010000000474974513, 'splitAngle': (18.0, 18.0, 22.0, 0.0), 'seed': 0, 'showLeaves': True, 'downAngle': (0.0, 26.209999084472656, 52.55999755859375, 30.0), 'leafDownAngle': 30.0, 'autoTaper': True, 'rMode': 'rotate', 'leafScaleX': 0.20000000298023224, 'leafScaleT': 0.10000000149011612, 'gust': 1.0, 'armAnim': False, 'wind': 1.0, 'leafRotateV': 15.0, 'baseSplits': 3, 'attractOut': (0.0, 0.800000011920929, 0.0, 0.0), 'armLevels': 2, 'leafAnim': False, 'ratioPower': 1.2000000476837158, 'splitHeight': 0.20000000298023224, 'splitByLen': True, 'af1': 1.0, 'branchDist': 1.5, 'closeTip': False, 'previewArm': False, 'attractUp': (3.5, -1.899843692779541, 0.0, 0.0), 'bevelRes': 1, 'pruneWidth': 0.3400000035762787, 'gustF': 0.07500000298023224, 'leafangle': -12.0, 'curveV': (20.0, 50.0, 75.0, 0.0), 'useOldDownAngle': True, 'leafDownAngleV': -10.0, 'frameRate': 1.0, 'splitAngleV': (5.0, 5.0, 5.0, 0.0), 'levels': 2, 'downAngleV': (0.0, 10.0, 10.0, 10.0), 'customShape': (0.5, 1.0, 0.30000001192092896, 0.5), 'curve': (0.0, -15.0, 0.0, 0.0)}
diff --git a/add_curve_sapling/presets/douglas_fir.py b/add_curve_sapling/presets/douglas_fir.py
index c9f01632..64f8cea2 100644
--- a/add_curve_sapling/presets/douglas_fir.py
+++ b/add_curve_sapling/presets/douglas_fir.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'pruneRatio': 1.0, 'wind': 1.0, 'prune': False, 'splitByLen': True, 'attractUp': (0.0, 0.3499999940395355, 0.25, 0.15000000596046448), 'segSplits': (0.0, 0.3499999940395355, 0.6000000238418579, 0.0), 'rMode': 'rotate', 'rotate': (99.5, 137.5, -45.0, -60.0), 'curve': (0.0, 20.0, -10.0, 0.0), 'af2': 1.0, 'seed': 0, 'length': (1.0, 0.20000000298023224, 0.550000011920929, 0.44999998807907104), 'attractOut': (0.0, 0.0, 0.0, 0.0), 'leafScaleT': 0.0, 'scaleV': 15.0, 'splitHeight': 0.20000000298023224, 'minRadius': 0.0020000000949949026, 'leafRotate': 137.5, 'curveRes': (12, 4, 3, 2), 'curveV': (40.0, 30.0, 15.0, 10.0), 'nrings': 0, 'levels': 4, 'frameRate': 1.0, 'ratioPower': 1.2000000476837158, 'leafDownAngle': 45.0, 'armLevels': 2, 'branches': (0, 75, 16, 10), 'splitAngleV': (0.0, 0.0, 0.0, 0.0), 'shape': '8', 'rotateV': (15.0, 0.0, 15.0, 45.0), 'loopFrames': 0, 'curveBack': (0.0, 0.0, 0.0, 0.0), 'taperCrown': 0.0, 'prunePowerLow': 0.0010000000474974513, 'handleType': '0', 'af3': 4.0, 'useParentAngle': True, 'customShape': (0.5, 1.0, 0.3499999940395355, 0.10000000149011612), 'scale0': 1.0, 'rootFlare': 1.2999999523162842, 'leafScaleV': 0.0, 'leafScale': 0.17000000178813934, 'leafangle': 0.0, 'scaleV0': 0.10000000149011612, 'downAngleV': (0.0, 30.0, 10.0, 10.0), 'af1': 1.0, 'autoTaper': True, 'scale': 35.0, 'gustF': 0.07500000298023224, 'ratio': 0.014999999664723873, 'leafScaleX': 1.0, 'shapeS': '7', 'bevelRes': 1, 'bevel': True, 'leaves': 25, 'splitAngle': (0.0, 12.0, 18.0, 0.0), 'downAngle': (90.0, 130.0, 45.0, 45.0), 'previewArm': False, 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'showLeaves': False, 'leafAnim': False, 'baseSize': 0.33000001311302185, 'gust': 1.0, 'horzLeaves': True, 'baseSize_s': 0.5, 'leafDownAngleV': 10.0, 'makeMesh': False, 'leafDist': '6', 'armAnim': False, 'baseSplits': 0, 'lengthV': (0.0, 0.10000000149011612, 0.25, 0.25), 'branchDist': 1.850000023841858, 'useArm': False, 'useOldDownAngle': False, 'taper': (1.0, 1.0, 1.0, 1.0), 'pruneBase': 0.30000001192092896, 'splitBias': 0.0, 'boneStep': (1, 1, 1, 1), 'leafShape': 'hex', 'resU': 4, 'prunePowerHigh': 0.5, 'closeTip': True, 'pruneWidth': 0.4000000059604645, 'leafRotateV': 0.0, 'pruneWidthPeak': 0.6000000238418579}
diff --git a/add_curve_sapling/presets/japanese_maple.py b/add_curve_sapling/presets/japanese_maple.py
index af2c1413..c191d57f 100644
--- a/add_curve_sapling/presets/japanese_maple.py
+++ b/add_curve_sapling/presets/japanese_maple.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'leafScaleT': -0.5, 'shapeS': '10', 'scaleV': 2.0, 'resU': 4, 'boneStep': (1, 1, 1, 1), 'af3': 4.0, 'baseSize': 0.4000000059604645, 'prunePowerLow': 0.0010000000474974513, 'leafRotateV': 0.0, 'rootFlare': 1.0, 'customShape': (0.699999988079071, 1.0, 0.20000000298023224, 0.800000011920929), 'attractOut': (0.0, 0.75, 0.25, 0.0), 'useArm': False, 'branches': (0, 50, 10, 16), 'leafDownAngle': 45.0, 'length': (1.0, 0.30000001192092896, 0.5, 0.20000000298023224), 'segSplits': (0.25, 0.4000000059604645, 0.5, 0.0), 'makeMesh': False, 'curveV': (400.0, 150.0, 100.0, 0.0), 'curveBack': (0.0, 0.0, 0.0, 0.0), 'af1': 1.0, 'closeTip': False, 'frameRate': 1.0, 'leafangle': -10.0, 'af2': 1.0, 'rMode': 'rotate', 'leafScaleV': 0.0, 'rotateV': (15.0, 0.0, 0.0, 0.0), 'useParentAngle': False, 'taperCrown': 0.0, 'minRadius': 0.001500000013038516, 'splitAngleV': (5.0, 5.0, 0.0, 0.0), 'scaleV0': 0.10000000149011612, 'bevel': True, 'leafDownAngleV': 10.0, 'previewArm': False, 'showLeaves': True, 'ratioPower': 1.25, 'handleType': '0', 'branchDist': 1.0, 'leafScaleX': 0.20000000298023224, 'prune': False, 'splitHeight': 0.30000001192092896, 'baseSplits': 2, 'baseSize_s': 0.25, 'downAngle': (90.0, 90.0, 30.0, 30.0), 'bevelRes': 1, 'leafAnim': False, 'loopFrames': 0, 'lengthV': (0.0, 0.0, 0.0, 0.0), 'gust': 1.0, 'downAngleV': (0.0, 90.0, 15.0, 10.0), 'leafRotate': 137.5, 'wind': 1.0, 'leaves': -5, 'curve': (0.0, -20.0, -20.0, 0.0), 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'pruneRatio': 1.0, 'pruneBase': 0.30000001192092896, 'armAnim': False, 'splitBias': 0.0, 'rotate': (99.5, 137.5, 137.5, 137.5), 'armLevels': 2, 'scale': 6.0, 'prunePowerHigh': 0.5, 'nrings': 0, 'splitByLen': True, 'leafShape': 'hex', 'splitAngle': (15.0, 20.0, 25.0, 0.0), 'ratio': 0.019999999552965164, 'scale0': 1.0, 'autoTaper': True, 'pruneWidth': 0.4000000059604645, 'leafScale': 0.17000000178813934, 'seed': 0, 'curveRes': (16, 5, 3, 1), 'horzLeaves': True, 'useOldDownAngle': False, 'levels': 4, 'pruneWidthPeak': 0.6000000238418579, 'attractUp': (0.0, -0.3499999940395355, -0.20000000298023224, 0.0), 'taper': (1.0, 1.0, 1.0, 1.0), 'leafDist': '6', 'gustF': 0.07500000298023224, 'shape': '8'}
diff --git a/add_curve_sapling/presets/quaking_aspen.py b/add_curve_sapling/presets/quaking_aspen.py
index 70e0a80b..8abea9c3 100644
--- a/add_curve_sapling/presets/quaking_aspen.py
+++ b/add_curve_sapling/presets/quaking_aspen.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'leafScale': 0.17000000178813934, 'autoTaper': True, 'customShape': (0.5, 1.0, 0.30000001192092896, 0.5), 'leafShape': 'hex', 'curve': (0.0, -40.0, -40.0, 0.0), 'ratio': 0.014999999664723873, 'splitBias': 0.0, 'pruneWidth': 0.4000000059604645, 'downAngleV': (0.0, 80.0, 10.0, 10.0), 'rotate': (99.5, 137.5, 137.5, 137.5), 'pruneRatio': 1.0, 'leafDownAngle': 45.0, 'makeMesh': False, 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'rMode': 'rotate', 'splitAngleV': (0.0, 0.0, 0.0, 0.0), 'branchDist': 1.0, 'bevel': True, 'minRadius': 0.001500000013038516, 'prune': False, 'leafRotateV': 0.0, 'splitAngle': (0.0, 0.0, 0.0, 0.0), 'armAnim': False, 'boneStep': (1, 1, 1, 1), 'pruneBase': 0.30000001192092896, 'taperCrown': 0.0, 'baseSplits': 0, 'baseSize_s': 0.25, 'handleType': '0', 'baseSize': 0.4000000059604645, 'af1': 1.0, 'levels': 2, 'leafScaleV': 0.0, 'resU': 4, 'seed': 0, 'downAngle': (90.0, 110.0, 45.0, 45.0), 'leafangle': 0.0, 'scaleV0': 0.10000000149011612, 'prunePowerHigh': 0.5, 'splitByLen': True, 'wind': 1.0, 'shape': '7', 'prunePowerLow': 0.0010000000474974513, 'scale': 13.0, 'leafAnim': False, 'curveBack': (0.0, 0.0, 0.0, 0.0), 'leafScaleX': 1.0, 'horzLeaves': True, 'splitHeight': 0.20000000298023224, 'leafScaleT': 0.0, 'scaleV': 3.0, 'leafDist': '6', 'nrings': 0, 'curveRes': (8, 5, 3, 1), 'shapeS': '4', 'bevelRes': 0, 'useOldDownAngle': False, 'useParentAngle': True, 'armLevels': 2, 'scale0': 1.0, 'taper': (1.0, 1.0, 1.0, 1.0), 'pruneWidthPeak': 0.6000000238418579, 'previewArm': False, 'leaves': 25, 'ratioPower': 1.100000023841858, 'gustF': 0.07500000298023224, 'curveV': (20.0, 50.0, 75.0, 0.0), 'showLeaves': False, 'frameRate': 1.0, 'length': (1.0, 0.30000001192092896, 0.6000000238418579, 0.44999998807907104), 'branches': (0, 50, 30, 10), 'useArm': False, 'loopFrames': 0, 'gust': 1.0, 'af3': 4.0, 'closeTip': False, 'leafRotate': 137.5, 'attractUp': (0.0, 0.0, 0.5, 0.5), 'leafDownAngleV': 10.0, 'rootFlare': 1.0, 'af2': 1.0, 'lengthV': (0.0, 0.0, 0.0, 0.0), 'rotateV': (15.0, 0.0, 0.0, 0.0), 'attractOut': (0.0, 0.0, 0.0, 0.0), 'segSplits': (0.0, 0.0, 0.0, 0.0)}
diff --git a/add_curve_sapling/presets/small_maple.py b/add_curve_sapling/presets/small_maple.py
index 8072d547..13d441a9 100644
--- a/add_curve_sapling/presets/small_maple.py
+++ b/add_curve_sapling/presets/small_maple.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'leafDownAngle': 45.0, 'handleType': '0', 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'useArm': False, 'rootFlare': 1.0, 'segSplits': (0.44999998807907104, 0.5, 0.800000011920929, 0.0), 'leafRotateV': 0.0, 'leaves': 32, 'baseSplits': 1, 'rotate': (99.5, 137.5, 137.5, 137.5), 'scale': 8.0, 'makeMesh': False, 'leafDownAngleV': 10.0, 'curve': (0.0, 30.0, 0.0, 0.0), 'splitBias': 0.0, 'leafScale': 0.18000000715255737, 'levels': 3, 'leafScaleT': 0.3499999940395355, 'seed': 0, 'autoTaper': True, 'pruneWidthPeak': 0.6000000238418579, 'branchDist': 1.25, 'prune': False, 'splitAngle': (8.0, 18.0, 18.0, 0.0), 'shapeS': '7', 'useParentAngle': True, 'af1': 1.0, 'armAnim': False, 'resU': 4, 'ratioPower': 1.2000000476837158, 'scaleV': 2.0, 'splitHeight': 0.20000000298023224, 'leafRotate': 137.5, 'customShape': (0.5, 1.0, 0.30000001192092896, 0.5), 'shape': '7', 'ratio': 0.019999999552965164, 'rMode': 'rotate', 'downAngle': (90.0, 48.0, 45.0, 45.0), 'bevelRes': 2, 'showLeaves': True, 'wind': 1.0, 'loopFrames': 0, 'splitByLen': True, 'lengthV': (0.0, 0.029999999329447746, 0.15000000596046448, 0.0), 'leafShape': 'hex', 'downAngleV': (0.0, 48.0, 10.0, 10.0), 'leafangle': -35.0, 'bevel': True, 'gustF': 0.07500000298023224, 'taper': (1.0, 1.0, 1.0, 1.0), 'previewArm': False, 'frameRate': 1.0, 'curveBack': (0.0, -30.0, -20.0, 0.0), 'taperCrown': 0.20000000298023224, 'rotateV': (15.0, 0.0, 0.0, 0.0), 'scaleV0': 0.20000000298023224, 'gust': 1.0, 'horzLeaves': True, 'attractUp': (-0.5, -0.699999988079071, 0.0, 0.0), 'splitAngleV': (2.0, 5.0, 5.0, 0.0), 'pruneRatio': 1.0, 'curveV': (10.0, 35.0, 35.0, 0.0), 'prunePowerHigh': 0.5, 'closeTip': False, 'leafScaleV': 0.20000000298023224, 'leafAnim': False, 'minRadius': 0.0020000000949949026, 'af3': 4.0, 'attractOut': (0.0, 0.4000000059604645, 0.5, 0.0), 'branches': (0, 110, 18, 10), 'leafScaleX': 0.6499999761581421, 'length': (1.0, 0.46000000834465027, 0.44999998807907104, 0.44999998807907104), 'useOldDownAngle': False, 'armLevels': 2, 'boneStep': (1, 1, 1, 1), 'pruneBase': 0.30000001192092896, 'curveRes': (8, 5, 3, 1), 'prunePowerLow': 0.0010000000474974513, 'af2': 1.0, 'pruneWidth': 0.4000000059604645, 'nrings': 0, 'baseSize_s': 0.25, 'baseSize': 0.2800000011920929, 'leafDist': '6', 'scale0': 1.0}
diff --git a/add_curve_sapling/presets/small_pine.py b/add_curve_sapling/presets/small_pine.py
index b0d2dc58..b5b41d61 100644
--- a/add_curve_sapling/presets/small_pine.py
+++ b/add_curve_sapling/presets/small_pine.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'downAngleV': (0.0, 42.0, 10.0, 10.0), 'useOldDownAngle': False, 'splitBias': 0.0, 'branchDist': 1.600000023841858, 'downAngle': (90.0, 110.0, 45.0, 45.0), 'leafScale': 0.20000000298023224, 'baseSize': 0.06799984723329544, 'shapeS': '4', 'leafScaleX': 0.019999999552965164, 'nrings': 7, 'gustF': 0.07500000298023224, 'showLeaves': True, 'taperCrown': 0.0, 'curveBack': (0.0, 0.0, 0.0, 0.0), 'leafShape': 'rect', 'makeMesh': False, 'scale0': 1.0, 'length': (1.0, 0.3199999928474426, 0.75, 0.44999998807907104), 'ratioPower': 1.0, 'taper': (1.0, 1.0, 1.0, 1.0), 'baseSize_s': 0.25, 'splitHeight': 0.20000000298023224, 'handleType': '0', 'pruneBase': 0.30000001192092896, 'attractUp': (2.0, 0.0, 0.5, 0.5), 'boneStep': (1, 1, 1, 1), 'seed': 0, 'leafDownAngle': 65.0, 'attractOut': (0.0, 0.0, 0.0, 0.0), 'leafAnim': False, 'gust': 1.0, 'curveV': (100.0, 100.0, 100.0, 0.0), 'splitAngle': (0.0, 22.0, 25.0, 0.0), 'prunePowerLow': 0.0010000000474974513, 'leafangle': -10.0, 'frameRate': 1.0, 'pruneRatio': 1.0, 'rMode': 'rotate', 'shape': '8', 'segSplits': (0.0, 0.30000001192092896, 0.4000000059604645, 0.0), 'branches': (0, 36, 7, 10), 'prunePowerHigh': 0.5, 'af1': 1.0, 'closeTip': False, 'splitAngleV': (0.0, 5.0, 0.0, 0.0), 'ratio': 0.019999999552965164, 'minRadius': 0.001500000013038516, 'levels': 3, 'leafRotate': 137.5, 'armLevels': 2, 'horzLeaves': False, 'pruneWidth': 0.4000000059604645, 'baseSplits': 0, 'scale': 4.0, 'leafScaleV': 0.10000000149011612, 'splitByLen': True, 'useParentAngle': True, 'previewArm': False, 'wind': 1.0, 'leafDist': '3', 'leafScaleT': 0.25, 'bevel': True, 'resU': 4, 'leafDownAngleV': 55.0, 'pruneWidthPeak': 0.6000000238418579, 'af3': 4.0, 'scaleV': 1.0, 'rootFlare': 1.0, 'loopFrames': 0, 'curve': (0.0, -40.0, -30.0, 0.0), 'leaves': 500, 'scaleV0': 0.10000000149011612, 'rotate': (99.5, 137.5, -90.0, 137.5), 'curveRes': (8, 5, 3, 1), 'useArm': False, 'af2': 1.0, 'bevelRes': 2, 'autoTaper': True, 'lengthV': (0.0, 0.15000000596046448, 0.25, 0.0), 'armAnim': False, 'prune': False, 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'leafRotateV': 30.0, 'customShape': (0.8999999761581421, 1.0, 0.20000000298023224, 0.20000000298023224), 'rotateV': (15.0, 0.0, 0.0, 0.0)}
diff --git a/add_curve_sapling/presets/weeping_willow.py b/add_curve_sapling/presets/weeping_willow.py
index a4efed38..65c570e3 100644
--- a/add_curve_sapling/presets/weeping_willow.py
+++ b/add_curve_sapling/presets/weeping_willow.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'showLeaves': False, 'leafScaleX': 0.20000000298023224, 'horzLeaves': False, 'useArm': False, 'rMode': 'rotate', 'branchDist': 1.5, 'scale': 15.0, 'armLevels': 2, 'gustF': 0.07500000298023224, 'closeTip': False, 'shape': '4', 'minRadius': 0.001500000013038516, 'leafScaleT': 0.0, 'leafDownAngle': 30.0, 'splitByLen': True, 'prunePowerLow': 0.0010000000474974513, 'splitBias': 0.0, 'autoTaper': True, 'leafRotateV': 30.0, 'scale0': 1.0, 'length': (0.75, 0.5, 1.5, 0.10000000149011612), 'lengthV': (0.0, 0.10000000149011612, 0.0, 0.0), 'bevel': True, 'baseSize': 0.20000000298023224, 'handleType': '1', 'ratioPower': 1.75, 'leafScaleV': 0.0, 'ratio': 0.02500000037252903, 'scaleV': 5.0, 'gust': 1.0, 'baseSplits': 2, 'loopFrames': 0, 'curve': (0.0, 20.0, -40.0, 0.0), 'pruneWidth': 0.5, 'shapeS': '4', 'splitAngleV': (0.0, 10.0, 20.0, 0.0), 'branches': (0, 35, 15, 1), 'frameRate': 1.0, 'splitAngle': (12.0, 30.0, 16.0, 0.0), 'seed': 2789, 'nrings': 0, 'previewArm': False, 'pruneWidthPeak': 0.6000000238418579, 'af1': 1.0, 'splitHeight': 0.20000000298023224, 'rotateV': (15.0, 15.0, 45.0, 0.0), 'attractUp': (0.0, 0.0, -2.75, -3.0), 'curveV': (150.0, 120.0, 0.0, 0.0), 'makeMesh': False, 'leaves': 150, 'curveBack': (0.0, 20.0, 0.0, 0.0), 'taper': (1.0, 1.0, 1.0, 1.0), 'resU': 4, 'useOldDownAngle': False, 'pruneRatio': 0.800000011920929, 'levels': 3, 'taperCrown': 0.0, 'attractOut': (0.0, 0.0, 0.0, 0.0), 'leafRotate': 137.5, 'prunePowerHigh': 0.20000000298023224, 'prune': False, 'leafangle': 0.0, 'bevelRes': 1, 'curveRes': (8, 16, 8, 1), 'rotate': (99.5, 137.5, -60.0, 140.0), 'pruneBase': 0.07000000029802322, 'segSplits': (0.10000000149011612, 0.20000000298023224, 0.20000000298023224, 0.0), 'scaleV0': 0.0, 'boneStep': (1, 1, 1, 1), 'useParentAngle': True, 'armAnim': False, 'wind': 1.0, 'leafDist': '10', 'leafScale': 0.25, 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'leafDownAngleV': 10.0, 'leafAnim': False, 'downAngle': (0.0, 20.0, 30.0, 20.0), 'af2': 1.0, 'af3': 4.0, 'downAngleV': (0.0, 20.0, 10.0, 10.0), 'customShape': (0.5, 1.0, 0.30000001192092896, 0.5), 'leafShape': 'hex', 'rootFlare': 1.0, 'baseSize_s': 0.25}
diff --git a/add_curve_sapling/presets/white_birch.py b/add_curve_sapling/presets/white_birch.py
index 6aa5829f..43bd4ac5 100644
--- a/add_curve_sapling/presets/white_birch.py
+++ b/add_curve_sapling/presets/white_birch.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'seed': 0, 'showLeaves': True, 'armLevels': 0, 'leafDist': '6', 'baseSize': 0.3499999940395355, 'loopFrames': 0, 'af3': 4.0, 'previewArm': False, 'leafangle': -45.0, 'useParentAngle': True, 'handleType': '0', 'branches': (0, 60, 30, 10), 'autoTaper': True, 'splitAngle': (12.0, 18.0, 16.0, 0.0), 'baseSize_s': 0.800000011920929, 'closeTip': False, 'af2': 1.0, 'prune': False, 'scale0': 1.0, 'rMode': 'rotate', 'useOldDownAngle': False, 'scaleV0': 0.10000000149011612, 'splitBias': 0.0, 'resU': 2, 'curveBack': (0.0, -5.0, 0.0, 0.0), 'scale': 12.0, 'shape': '8', 'leafDownAngle': 45.0, 'af1': 1.0, 'ratio': 0.019999999552965164, 'horzLeaves': True, 'leafRotate': 137.5, 'minRadius': 0.0020000000949949026, 'bevelRes': 2, 'splitByLen': True, 'rootFlare': 1.149999976158142, 'makeMesh': False, 'downAngleV': (0.0, 25.0, 30.0, 10.0), 'levels': 3, 'scaleV': 2.0, 'armAnim': False, 'lengthV': (0.05000000074505806, 0.20000000298023224, 0.3499999940395355, 0.0), 'pruneWidth': 0.3100000023841858, 'gustF': 0.07500000298023224, 'taper': (1.0, 1.0, 1.0, 1.0), 'splitAngleV': (2.0, 2.0, 0.0, 0.0), 'prunePowerLow': 0.0010000000474974513, 'leafScaleT': 0.20000000298023224, 'leafScaleX': 0.5, 'leafRotateV': 0.0, 'ratioPower': 1.399999976158142, 'segSplits': (0.3499999940395355, 0.3499999940395355, 0.3499999940395355, 0.0), 'downAngle': (90.0, 60.0, 50.0, 45.0), 'rotateV': (0.0, 0.0, 0.0, 0.0), 'gust': 1.0, 'attractUp': (0.0, -1.0, -0.6499999761581421, 0.0), 'leafScaleV': 0.25, 'frameRate': 1.0, 'curveV': (100.0, 80.0, 80.0, 0.0), 'boneStep': (1, 1, 1, 1), 'customShape': (0.699999988079071, 1.0, 0.30000001192092896, 0.5900000333786011), 'pruneBase': 0.30000001192092896, 'leafAnim': False, 'curveRes': (10, 8, 3, 1), 'nrings': 0, 'bevel': True, 'taperCrown': 0.0, 'baseSplits': 2, 'leafShape': 'hex', 'splitHeight': 0.550000011920929, 'wind': 1.0, 'curve': (0.0, -30.0, -25.0, 0.0), 'rotate': (137.5, 137.5, 137.5, 137.5), 'length': (1.0, 0.33000001311302185, 0.375, 0.44999998807907104), 'leafScale': 0.20000000298023224, 'attractOut': (0.0, 0.20000000298023224, 0.25, 0.0), 'prunePowerHigh': 0.10000000149011612, 'branchDist': 1.5, 'useArm': False, 'pruneRatio': 1.0, 'shapeS': '7', 'leafDownAngleV': 10.0, 'pruneWidthPeak': 0.5, 'radiusTweak': (1.0, 1.0, 1.0, 1.0), 'leaves': 16}
diff --git a/add_curve_sapling/presets/willow.py b/add_curve_sapling/presets/willow.py
index 3384eb19..c52a501e 100644
--- a/add_curve_sapling/presets/willow.py
+++ b/add_curve_sapling/presets/willow.py
@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 {'curveRes': (8, 16, 12, 1), 'scaleV0': 0.0, 'pruneRatio': 1.0, 'rotate': (0.0, -120.0, -120.0, 140.0), 'resU': 4, 'levels': 2, 'frameRate': 1.0, 'ratioPower': 2.0, 'windGust': 0.0, 'branches': (0, 25, 10, 300), 'attractUp': -3.0, 'bevel': True, 'windSpeed': 2.0, 'rotateV': (0.0, 30.0, 30.0, 0.0), 'segSplits': (0.10000000149011612, 0.20000000298023224, 0.20000000298023224, 0.0), 'handleType': '1', 'shape': '3', 'curveV': (120.0, 90.0, 0.0, 0.0), 'scale': 15.0, 'leafShape': 'hex', 'showLeaves': False, 'ratio': 0.029999999329447746, 'leaves': 15.0, 'armAnim': False, 'leafScale': 0.11999999731779099, 'leafDist': '4', 'useArm': False, 'splitAngle': (3.0, 30.0, 45.0, 0.0), 'lengthV': (0.0, 0.10000000149011612, 0.0, 0.0), 'seed': 0, 'scaleV': 5.0, 'startCurv': 0.0, 'downAngle': (0.0, 20.0, 30.0, 20.0), 'pruneWidth': 0.4000000059604645, 'baseSize': 0.05000000074505806, 'bevelRes': 0, 'length': (0.800000011920929, 0.5, 1.5, 0.10000000149011612), 'downAngleV': (0.0, 10.0, 10.0, 10.0), 'prune': False, 'curve': (0.0, 40.0, 0.0, 0.0), 'taper': (1.0, 1.0, 1.0, 1.0), 'prunePowerHigh': 0.5, 'leafScaleX': 0.20000000298023224, 'curveBack': (20.0, 80.0, 0.0, 0.0), 'bend': 0.0, 'scale0': 1.0, 'prunePowerLow': 0.0010000000474974513, 'splitAngleV': (0.0, 10.0, 20.0, 0.0), 'baseSplits': 2, 'pruneWidthPeak': 0.6000000238418579}
diff --git a/add_mesh_extra_objects/Blocks.py b/add_mesh_extra_objects/Blocks.py
index 31db7807..928ed1d6 100644
--- a/add_mesh_extra_objects/Blocks.py
+++ b/add_mesh_extra_objects/Blocks.py
@@ -1,4 +1,6 @@
-# GPL # "authors": dudecon, jambay
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Authors: dudecon, jambay
 
 # Module notes:
 #
diff --git a/add_mesh_extra_objects/add_empty_as_parent.py b/add_mesh_extra_objects/add_empty_as_parent.py
index da4295ff..62b7751c 100644
--- a/add_mesh_extra_objects/add_empty_as_parent.py
+++ b/add_mesh_extra_objects/add_empty_as_parent.py
@@ -1,4 +1,6 @@
-# GPL # Original Author Liero #
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Original Author Liero
 
 import bpy
 from bpy.types import Operator
diff --git a/add_mesh_extra_objects/add_mesh_3d_function_surface.py b/add_mesh_extra_objects/add_mesh_3d_function_surface.py
index c4520adc..b7025bd4 100644
--- a/add_mesh_extra_objects/add_mesh_3d_function_surface.py
+++ b/add_mesh_extra_objects/add_mesh_3d_function_surface.py
@@ -1,4 +1,6 @@
-# GPL # original by Buerbaum Martin (Pontiac), Elod Csirmaz
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Original by Buerbaum Martin (Pontiac), Elod Csirmaz
 
 import bpy
 import math
diff --git a/add_mesh_extra_objects/add_mesh_beam_builder.py b/add_mesh_extra_objects/add_mesh_beam_builder.py
index 0cc43e0f..f4a4a7d2 100644
--- a/add_mesh_extra_objects/add_mesh_beam_builder.py
+++ b/add_mesh_extra_objects/add_mesh_beam_builder.py
@@ -1,4 +1,6 @@
-# GPL # "author": revolt_randy, Jambay
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: revolt_randy, Jambay
 
 # Create "Beam" primitives. Based on original script by revolt_randy
 
diff --git a/add_mesh_extra_objects/add_mesh_gears.py b/add_mesh_extra_objects/add_mesh_gears.py
index 4d9f0168..b74ac936 100644
--- a/add_mesh_extra_objects/add_mesh_gears.py
+++ b/add_mesh_extra_objects/add_mesh_gears.py
@@ -1,4 +1,5 @@
-# GPL # (c) 2009, 2010 Michel J. Anders (varkenvarken)
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Copyright 2009-2010 Michel J. Anders (varkenvarken)
 
 import bpy
 from bpy.types import Operator
diff --git a/add_mesh_extra_objects/add_mesh_gemstones.py b/add_mesh_extra_objects/add_mesh_gemstones.py
index 92374118..f30911c5 100644
--- a/add_mesh_extra_objects/add_mesh_gemstones.py
+++ b/add_mesh_extra_objects/add_mesh_gemstones.py
@@ -1,4 +1,6 @@
-# GPL # "author": "Pontiac, Fourmadmen, Dreampainter"
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Pontiac, Fourmadmen, Dreampainter
 
 import bpy
 from bpy.types import Operator
diff --git a/add_mesh_extra_objects/add_mesh_honeycomb.py b/add_mesh_extra_objects/add_mesh_honeycomb.py
index bb6734a4..5c72f952 100644
--- a/add_mesh_extra_objects/add_mesh_honeycomb.py
+++ b/add_mesh_extra_objects/add_mesh_honeycomb.py
@@ -1,4 +1,6 @@
-# GPL # "author": "Kayo Phoenix"
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Kayo Phoenix
 
 import bpy
 from bpy_extras import object_utils
diff --git a/add_mesh_extra_objects/add_mesh_menger_sponge.py b/add_mesh_extra_objects/add_mesh_menger_sponge.py
index 1e932e20..bf723441 100644
--- a/add_mesh_extra_objects/add_mesh_menger_sponge.py
+++ b/add_mesh_extra_objects/add_mesh_menger_sponge.py
@@ -1,6 +1,5 @@
-# -*- coding: utf-8 -*-
-# Copyright (c) 2015 sugiany
-# This file is distributed under the MIT License. See the LICENSE.md for more details.
+# SPDX-License-Identifier: MIT
+# Copyright 2015 Sugiany
 
 import bpy
 
diff --git a/add_mesh_extra_objects/add_mesh_pipe_joint.py b/add_mesh_extra_objects/add_mesh_pipe_joint.py
index 91c64e2f..52103992 100644
--- a/add_mesh_extra_objects/add_mesh_pipe_joint.py
+++ b/add_mesh_extra_objects/add_mesh_pipe_joint.py
@@ -1,4 +1,6 @@
-# GPL # "author": "Buerbaum Martin (Pontiac)"
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Buerbaum Martin (Pontiac)
 
 import bpy, bmesh
 from math import sin, cos, tan, pi, radians
diff --git a/add_mesh_extra_objects/add_mesh_pyramid.py b/add_mesh_extra_objects/add_mesh_pyramid.py
index 58fafb04..1b735891 100644
--- a/add_mesh_extra_objects/add_mesh_pyramid.py
+++ b/add_mesh_extra_objects/add_mesh_pyramid.py
@@ -1,4 +1,6 @@
-# GPL # "author": "Phil Cote, cotejrp1, (http://www.blenderaddons.com)"
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Phil Cote, cotejrp1, (http://www.blenderaddons.com)
 
 import bpy
 import bmesh
diff --git a/add_mesh_extra_objects/add_mesh_rocks/randomize_texture.py b/add_mesh_extra_objects/add_mesh_rocks/randomize_texture.py
index 3b1c4565..8fc92890 100644
--- a/add_mesh_extra_objects/add_mesh_rocks/randomize_texture.py
+++ b/add_mesh_extra_objects/add_mesh_rocks/randomize_texture.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # This try block allows for the script to psudo-intelligently select the
 # appropriate random to use.  If Numpy's random is present it will use that.
 # If Numpy's random is not present, it will through a "module not found"
diff --git a/add_mesh_extra_objects/add_mesh_round_brilliant.py b/add_mesh_extra_objects/add_mesh_round_brilliant.py
index 874a26db..b1a93012 100644
--- a/add_mesh_extra_objects/add_mesh_round_brilliant.py
+++ b/add_mesh_extra_objects/add_mesh_round_brilliant.py
@@ -1,4 +1,5 @@
-# GPL "author": "Dominic Kröper, (dommetysk)"
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Author: Dominic Kröper, (dommetysk)
 
 import bpy
 from math import (
diff --git a/add_mesh_extra_objects/add_mesh_round_cube.py b/add_mesh_extra_objects/add_mesh_round_cube.py
index b48e9a69..3daf57a1 100644
--- a/add_mesh_extra_objects/add_mesh_round_cube.py
+++ b/add_mesh_extra_objects/add_mesh_round_cube.py
@@ -1,4 +1,6 @@
-# GPL # Author: Alain Ducharme (phymec)
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Alain Ducharme (phymec)
 
 import bpy
 from bpy_extras import object_utils
diff --git a/add_mesh_extra_objects/add_mesh_solid.py b/add_mesh_extra_objects/add_mesh_solid.py
index 59e070df..0d1a72c5 100644
--- a/add_mesh_extra_objects/add_mesh_solid.py
+++ b/add_mesh_extra_objects/add_mesh_solid.py
@@ -1,4 +1,6 @@
-# GPL # "author": "DreamPainter"
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: DreamPainter
 
 import bpy
 from math import sqrt
diff --git a/add_mesh_extra_objects/add_mesh_star.py b/add_mesh_extra_objects/add_mesh_star.py
index 2bede081..f12427cf 100644
--- a/add_mesh_extra_objects/add_mesh_star.py
+++ b/add_mesh_extra_objects/add_mesh_star.py
@@ -1,4 +1,6 @@
-# GPL Original by Fourmadmen
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Original by Fourmadmen
 
 import bpy
 from mathutils import (
diff --git a/add_mesh_extra_objects/add_mesh_supertoroid.py b/add_mesh_extra_objects/add_mesh_supertoroid.py
index 8a87a289..e325cffc 100644
--- a/add_mesh_extra_objects/add_mesh_supertoroid.py
+++ b/add_mesh_extra_objects/add_mesh_supertoroid.py
@@ -1,4 +1,6 @@
-# GPL # "author": "DreamPainter"
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: DreamPainter
 
 import bpy
 from bpy.props import (
diff --git a/add_mesh_extra_objects/add_mesh_torusknot.py b/add_mesh_extra_objects/add_mesh_torusknot.py
index 39e985c3..28c79027 100644
--- a/add_mesh_extra_objects/add_mesh_torusknot.py
+++ b/add_mesh_extra_objects/add_mesh_torusknot.py
@@ -1,4 +1,6 @@
-# GPL #  Author, Anthony D'Agostino
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Anthony D'Agostino
 
 import bpy
 from mathutils import Vector
diff --git a/add_mesh_extra_objects/add_mesh_triangles.py b/add_mesh_extra_objects/add_mesh_triangles.py
index 5373c5fb..f0a45ba8 100644
--- a/add_mesh_extra_objects/add_mesh_triangles.py
+++ b/add_mesh_extra_objects/add_mesh_triangles.py
@@ -1,4 +1,5 @@
-# GPL # "author": Sjaak-de-Draak
+# SPDX-License-Identifier: GPL-2.0-or-later
+# Author: Sjaak-de-Draak
 
 bl_info = {
     "name": "Triangles",
diff --git a/add_mesh_extra_objects/add_mesh_twisted_torus.py b/add_mesh_extra_objects/add_mesh_twisted_torus.py
index bb3bd483..1a2b47f7 100644
--- a/add_mesh_extra_objects/add_mesh_twisted_torus.py
+++ b/add_mesh_extra_objects/add_mesh_twisted_torus.py
@@ -1,4 +1,6 @@
-# GPL # "author": Paulo_Gomes
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Paulo_Gomes
 
 import bpy
 from mathutils import Quaternion, Vector
diff --git a/add_mesh_extra_objects/add_mesh_vertex.py b/add_mesh_extra_objects/add_mesh_vertex.py
index 88b9d345..4ee3ad85 100644
--- a/add_mesh_extra_objects/add_mesh_vertex.py
+++ b/add_mesh_extra_objects/add_mesh_vertex.py
@@ -1,4 +1,6 @@
-# GPL # Originals by meta-androcto, Pablo Vazquez, Liero, Richard Wilks
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Originals by meta-androcto, Pablo Vazquez, Liero, Richard Wilks
 
 import bpy
 from bpy.types import Operator
diff --git a/add_mesh_geodesic_domes/add_shape_geodesic.py b/add_mesh_geodesic_domes/add_shape_geodesic.py
index d461bd15..e647ba35 100644
--- a/add_mesh_geodesic_domes/add_shape_geodesic.py
+++ b/add_mesh_geodesic_domes/add_shape_geodesic.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 import mathutils
 
diff --git a/add_mesh_geodesic_domes/forms_271.py b/add_mesh_geodesic_domes/forms_271.py
index f4dd5119..c7a933a3 100644
--- a/add_mesh_geodesic_domes/forms_271.py
+++ b/add_mesh_geodesic_domes/forms_271.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from math import sin, cos, sqrt
 from .vefm_271 import *
 
diff --git a/add_mesh_geodesic_domes/geodesic_classes_271.py b/add_mesh_geodesic_domes/geodesic_classes_271.py
index 6f54bff7..3b3a0387 100644
--- a/add_mesh_geodesic_domes/geodesic_classes_271.py
+++ b/add_mesh_geodesic_domes/geodesic_classes_271.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from .vefm_271 import mesh, vertex, edge, face
 from math import pi, acos, sin, cos, atan, tan, fabs, sqrt
 
diff --git a/add_mesh_geodesic_domes/third_domes_panel_271.py b/add_mesh_geodesic_domes/third_domes_panel_271.py
index d95de427..148a802f 100644
--- a/add_mesh_geodesic_domes/third_domes_panel_271.py
+++ b/add_mesh_geodesic_domes/third_domes_panel_271.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 import os
 from . import vefm_271
diff --git a/add_mesh_geodesic_domes/vefm_271.py b/add_mesh_geodesic_domes/vefm_271.py
index bc6a38dc..f7b71dfd 100644
--- a/add_mesh_geodesic_domes/vefm_271.py
+++ b/add_mesh_geodesic_domes/vefm_271.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # vert class and overloading experiments
 import bpy
 # PKHG>NEEDED?
diff --git a/ant_landscape/eroder.py b/ant_landscape/eroder.py
index eee91bf7..1859ab66 100644
--- a/ant_landscape/eroder.py
+++ b/ant_landscape/eroder.py
@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-
 from time import time
 import unittest
 import sys
diff --git a/ant_landscape/stats.py b/ant_landscape/stats.py
index 5c37d2ba..c8793dd9 100644
--- a/ant_landscape/stats.py
+++ b/ant_landscape/stats.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from time import time
 
 try:
diff --git a/ant_landscape/test.py b/ant_landscape/test.py
index d56815f2..39d060c4 100644
--- a/ant_landscape/test.py
+++ b/ant_landscape/test.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from numpy import *
 
 if __name__ == '__main__':
diff --git a/ant_landscape/utils.py b/ant_landscape/utils.py
index 6588f75b..7687bd54 100644
--- a/ant_landscape/utils.py
+++ b/ant_landscape/utils.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 numexpr_available=False
 try:
     import numexpr
diff --git a/curve_tools/auto_loft.py b/curve_tools/auto_loft.py
index 17705cc9..3092e6b8 100644
--- a/curve_tools/auto_loft.py
+++ b/curve_tools/auto_loft.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 from bpy.props import BoolProperty
 from bpy.types import Operator, Panel
diff --git a/curve_tools/intersections.py b/curve_tools/intersections.py
index f0b8e96f..113a97ed 100644
--- a/curve_tools/intersections.py
+++ b/curve_tools/intersections.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 from . import mathematics
 from . import curves
diff --git a/curve_tools/mathematics.py b/curve_tools/mathematics.py
index 4a61af4d..555c3f65 100644
--- a/curve_tools/mathematics.py
+++ b/curve_tools/mathematics.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from mathutils import *
 
 
diff --git a/curve_tools/properties.py b/curve_tools/properties.py
index d6fe9e0f..d984f67b 100644
--- a/curve_tools/properties.py
+++ b/curve_tools/properties.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import time
 
 import bpy
diff --git a/curve_tools/remove_doubles.py b/curve_tools/remove_doubles.py
index f0b3dbb5..c63d82be 100644
--- a/curve_tools/remove_doubles.py
+++ b/curve_tools/remove_doubles.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy, mathutils
 from . import util
 
diff --git a/curve_tools/surfaces.py b/curve_tools/surfaces.py
index 7fa484a7..2d89115c 100644
--- a/curve_tools/surfaces.py
+++ b/curve_tools/surfaces.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 import bmesh
 
diff --git a/curve_tools/util.py b/curve_tools/util.py
index 110b8b83..59603186 100644
--- a/curve_tools/util.py
+++ b/curve_tools/util.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 from mathutils import *
 
diff --git a/io_coat3D/folders.py b/io_coat3D/folders.py
index ed348cfa..95dc6e51 100644
--- a/io_coat3D/folders.py
+++ b/io_coat3D/folders.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 import os
 
diff --git a/io_coat3D/updateimage.py b/io_coat3D/updateimage.py
index 2b967fd7..509f2b2e 100644
--- a/io_coat3D/updateimage.py
+++ b/io_coat3D/updateimage.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 import os
 
diff --git a/io_export_dxf/draw_blenders/__init__.py b/io_export_dxf/draw_blenders/__init__.py
index e2a7d030..79f9fdcb 100644
--- a/io_export_dxf/draw_blenders/__init__.py
+++ b/io_export_dxf/draw_blenders/__init__.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 """ NOTE:
 This stuff was in original code but it seems it will be no longer needed.
 NOT USED now.
diff --git a/io_export_dxf/model/migiusModel.py b/io_export_dxf/model/migiusModel.py
index 25813395..a33f47f7 100644
--- a/io_export_dxf/model/migiusModel.py
+++ b/io_export_dxf/model/migiusModel.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 """
 Created on Sep 2, 2011
 
diff --git a/io_export_dxf/model/model.py b/io_export_dxf/model/model.py
index 698f5102..a91799f4 100644
--- a/io_export_dxf/model/model.py
+++ b/io_export_dxf/model/model.py
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 class DxfDrawing(object):
     """
diff --git a/io_export_dxf/primitive_exporters/__init__.py b/io_export_dxf/primitive_exporters/__init__.py
index d1cfad46..caf90d57 100644
--- a/io_export_dxf/primitive_exporters/__init__.py
+++ b/io_export_dxf/primitive_exporters/__init__.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 """
 This package contains actual primitive exporter classes.
 They are imported and instantiated according object type
diff --git a/io_export_dxf/primitive_exporters/base_exporter.py b/io_export_dxf/primitive_exporters/base_exporter.py
index beb97f82..02d2747e 100644
--- a/io_export_dxf/primitive_exporters/base_exporter.py
+++ b/io_export_dxf/primitive_exporters/base_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import mathutils
 
 class BasePrimitiveDXFExporter(object):
diff --git a/io_export_dxf/primitive_exporters/camera_exporter.py b/io_export_dxf/primitive_exporters/camera_exporter.py
index e31166ed..d447f506 100644
--- a/io_export_dxf/primitive_exporters/camera_exporter.py
+++ b/io_export_dxf/primitive_exporters/camera_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from .base_exporter import BasePrimitiveDXFExporter
 
 
diff --git a/io_export_dxf/primitive_exporters/curve_exporter.py b/io_export_dxf/primitive_exporters/curve_exporter.py
index 09372cad..76316656 100644
--- a/io_export_dxf/primitive_exporters/curve_exporter.py
+++ b/io_export_dxf/primitive_exporters/curve_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from .base_exporter import BasePrimitiveDXFExporter
 
 
diff --git a/io_export_dxf/primitive_exporters/empty_exporter.py b/io_export_dxf/primitive_exporters/empty_exporter.py
index e849409e..4d12c3a2 100644
--- a/io_export_dxf/primitive_exporters/empty_exporter.py
+++ b/io_export_dxf/primitive_exporters/empty_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from .base_exporter import BasePrimitiveDXFExporter
 
 
diff --git a/io_export_dxf/primitive_exporters/insert_exporter.py b/io_export_dxf/primitive_exporters/insert_exporter.py
index c912d321..afd4e97d 100644
--- a/io_export_dxf/primitive_exporters/insert_exporter.py
+++ b/io_export_dxf/primitive_exporters/insert_exporter.py
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 from .base_exporter import BasePrimitiveDXFExporter
 
diff --git a/io_export_dxf/primitive_exporters/lamp_exporter.py b/io_export_dxf/primitive_exporters/lamp_exporter.py
index 849f0984..fee4787e 100644
--- a/io_export_dxf/primitive_exporters/lamp_exporter.py
+++ b/io_export_dxf/primitive_exporters/lamp_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from .base_exporter import BasePrimitiveDXFExporter
 
 
diff --git a/io_export_dxf/primitive_exporters/mesh_exporter.py b/io_export_dxf/primitive_exporters/mesh_exporter.py
index 225c60d84..b60c8c92 100644
--- a/io_export_dxf/primitive_exporters/mesh_exporter.py
+++ b/io_export_dxf/primitive_exporters/mesh_exporter.py
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import mathutils
 from .base_exporter import BasePrimitiveDXFExporter
diff --git a/io_export_dxf/primitive_exporters/text_exporter.py b/io_export_dxf/primitive_exporters/text_exporter.py
index fe997614..eb2ef204 100644
--- a/io_export_dxf/primitive_exporters/text_exporter.py
+++ b/io_export_dxf/primitive_exporters/text_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from .base_exporter import BasePrimitiveDXFExporter
 
 
diff --git a/io_export_dxf/primitive_exporters/viewborder_exporter.py b/io_export_dxf/primitive_exporters/viewborder_exporter.py
index 091cf63b..1fcd228d 100644
--- a/io_export_dxf/primitive_exporters/viewborder_exporter.py
+++ b/io_export_dxf/primitive_exporters/viewborder_exporter.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from base_exporter import BasePrimitiveDXFExporter
 
 
diff --git a/io_import_dxf/dxfgrabber/__init__.py b/io_import_dxf/dxfgrabber/__init__.py
index 5fe0fefa..f46c691e 100644
--- a/io_import_dxf/dxfgrabber/__init__.py
+++ b/io_import_dxf/dxfgrabber/__init__.py
@@ -1,7 +1,8 @@
-# dxfgrabber - copyright (C) 2012 by Manfred Moitzi (mozman)
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi (mozman)
+
 # Purpose: grab information from DXF drawings - all DXF versions supported
 # Created: 21.07.2012
-# License: MIT License
 
 version = (0, 8, 4)
 VERSION = "%d.%d.%d" % version
diff --git a/io_import_dxf/dxfgrabber/acdsdata.py b/io_import_dxf/dxfgrabber/acdsdata.py
index b864fff0..7a92d4cf 100644
--- a/io_import_dxf/dxfgrabber/acdsdata.py
+++ b/io_import_dxf/dxfgrabber/acdsdata.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2014 Manfred Moitzi
+
 # Purpose: acdsdata section manager
 # Created: 05.05.2014
-# Copyright (C) 2014, Manfred Moitzi
-# License: MIT License
 
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
diff --git a/io_import_dxf/dxfgrabber/blockssection.py b/io_import_dxf/dxfgrabber/blockssection.py
index a64a364e..5decd5c7 100644
--- a/io_import_dxf/dxfgrabber/blockssection.py
+++ b/io_import_dxf/dxfgrabber/blockssection.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2011 Manfred Moitzi
+
 # Purpose: blocks section
 # Created: 09.08.2012, taken from my package ezdxf
-# Copyright (C) 2011, Manfred Moitzi
-# License: MIT-License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/codepage.py b/io_import_dxf/dxfgrabber/codepage.py
index 47e8e3ea..69f0d1b0 100644
--- a/io_import_dxf/dxfgrabber/codepage.py
+++ b/io_import_dxf/dxfgrabber/codepage.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: codepage handling
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/color.py b/io_import_dxf/dxfgrabber/color.py
index ae999804..a83aee4f 100644
--- a/io_import_dxf/dxfgrabber/color.py
+++ b/io_import_dxf/dxfgrabber/color.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: MIT
+
 __author__ = 'manfred'
 
 
diff --git a/io_import_dxf/dxfgrabber/const.py b/io_import_dxf/dxfgrabber/const.py
index cf8c6613..1bae7fa0 100644
--- a/io_import_dxf/dxfgrabber/const.py
+++ b/io_import_dxf/dxfgrabber/const.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: constant values
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/decode.py b/io_import_dxf/dxfgrabber/decode.py
index 3187cc8f..da3d497c 100644
--- a/io_import_dxf/dxfgrabber/decode.py
+++ b/io_import_dxf/dxfgrabber/decode.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2014 Manfred Moitzi
+
 # Purpose: decode DXF proprietary data
 # Created: 01.05.2014
-# Copyright (C) 2014, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/defaultchunk.py b/io_import_dxf/dxfgrabber/defaultchunk.py
index 1df9969a..e953d3ec 100644
--- a/io_import_dxf/dxfgrabber/defaultchunk.py
+++ b/io_import_dxf/dxfgrabber/defaultchunk.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: handle default chunk
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/drawing.py b/io_import_dxf/dxfgrabber/drawing.py
index db739b23..492e86f9 100644
--- a/io_import_dxf/dxfgrabber/drawing.py
+++ b/io_import_dxf/dxfgrabber/drawing.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: handle drawing data of DXF files
 # Created: 21.07.12
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
 
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/dxfentities.py b/io_import_dxf/dxfgrabber/dxfentities.py
index ea2eb9d0..f9c9e4bc 100644
--- a/io_import_dxf/dxfgrabber/dxfentities.py
+++ b/io_import_dxf/dxfgrabber/dxfentities.py
@@ -1,8 +1,9 @@
-# encoding: utf-8
+# SPDX-License-Identifier: MIT
+# Copyright 2016 Manfred Moitzi
+
 # Purpose: entity classes, new implementation without dxf12/dxf13 layer
 # Created: 17.04.2016
-# Copyright (C) 2016, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/dxfobjects.py b/io_import_dxf/dxfgrabber/dxfobjects.py
index c7ee320b..f3ef149b 100644
--- a/io_import_dxf/dxfgrabber/dxfobjects.py
+++ b/io_import_dxf/dxfgrabber/dxfobjects.py
@@ -1,8 +1,9 @@
-# encoding: utf-8
+# SPDX-License-Identifier: MIT
+# Copyright 2016 Manfred Moitzi
+
 # Purpose: objects classes
 # Created: 17.04.2016
-# Copyright (C) 2016, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/entitysection.py b/io_import_dxf/dxfgrabber/entitysection.py
index cd717c56..2e27b657 100644
--- a/io_import_dxf/dxfgrabber/entitysection.py
+++ b/io_import_dxf/dxfgrabber/entitysection.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: handle entity section
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/headersection.py b/io_import_dxf/dxfgrabber/headersection.py
index 5c6d1622..eead8d01 100755
--- a/io_import_dxf/dxfgrabber/headersection.py
+++ b/io_import_dxf/dxfgrabber/headersection.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: handle header section
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/juliandate.py b/io_import_dxf/dxfgrabber/juliandate.py
index be8a3826..5b8c7567 100644
--- a/io_import_dxf/dxfgrabber/juliandate.py
+++ b/io_import_dxf/dxfgrabber/juliandate.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2011 Manfred Moitzi
+
 # Purpose: julian date
 # Created: 21.03.2011
-# Copyright (C) 2011, Manfred Moitzi
-# License: MIT License
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/layers.py b/io_import_dxf/dxfgrabber/layers.py
index a82e5ec8..028df423 100644
--- a/io_import_dxf/dxfgrabber/layers.py
+++ b/io_import_dxf/dxfgrabber/layers.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: handle layers
 # Created: 21.07.12
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
 
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/linetypes.py b/io_import_dxf/dxfgrabber/linetypes.py
index 4d7caba6..89307b1d 100644
--- a/io_import_dxf/dxfgrabber/linetypes.py
+++ b/io_import_dxf/dxfgrabber/linetypes.py
@@ -1,6 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2014 Manfred Moitzi
+
 # Purpose: handle linetypes table
 # Created: 06.01.2014
-# Copyright (C) 2014, Manfred Moitzi
 # License: MIT License
 
 __author__ = "mozman <mozman@gmx.at>"
diff --git a/io_import_dxf/dxfgrabber/sections.py b/io_import_dxf/dxfgrabber/sections.py
index 697263db..29980783 100755
--- a/io_import_dxf/dxfgrabber/sections.py
+++ b/io_import_dxf/dxfgrabber/sections.py
@@ -1,7 +1,8 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012, Manfred Moitzi
+
 # Purpose: handle dxf sections
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/styles.py b/io_import_dxf/dxfgrabber/styles.py
index 5d056f31..0104464f 100644
--- a/io_import_dxf/dxfgrabber/styles.py
+++ b/io_import_dxf/dxfgrabber/styles.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2014 Manfred Moitzi
+
 # Purpose: handle text styles
 # Created: 06.01.2014
-# Copyright (C) 2014, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/tablessection.py b/io_import_dxf/dxfgrabber/tablessection.py
index 345487fa..9c1599cb 100644
--- a/io_import_dxf/dxfgrabber/tablessection.py
+++ b/io_import_dxf/dxfgrabber/tablessection.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: handle tables section
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/io_import_dxf/dxfgrabber/tags.py b/io_import_dxf/dxfgrabber/tags.py
index 89354b8c..ded46f8a 100644
--- a/io_import_dxf/dxfgrabber/tags.py
+++ b/io_import_dxf/dxfgrabber/tags.py
@@ -1,7 +1,9 @@
+# SPDX-License-Identifier: MIT
+# Copyright 2012 Manfred Moitzi
+
 # Purpose: tag reader
 # Created: 21.07.2012, taken from my ezdxf project
-# Copyright (C) 2012, Manfred Moitzi
-# License: MIT License
+
 from __future__ import unicode_literals
 __author__ = "mozman <mozman@gmx.at>"
 
diff --git a/mesh_snap_utilities_line/keys.py b/mesh_snap_utilities_line/keys.py
index 29523966..6fcd2986 100644
--- a/mesh_snap_utilities_line/keys.py
+++ b/mesh_snap_utilities_line/keys.py
@@ -1,5 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
 
-#km_snap_utilities_modal_keymap = "Snap Utilities Modal Map"
+# km_snap_utilities_modal_keymap = "Snap Utilities Modal Map"
 
 km_tool_snap_utilities_line = "3D View Tool: Edit Mesh, Make Line"
 
diff --git a/mesh_tools/mesh_cut_faces.py b/mesh_tools/mesh_cut_faces.py
index 99f7c8ac..c3e999c3 100644
--- a/mesh_tools/mesh_cut_faces.py
+++ b/mesh_tools/mesh_cut_faces.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 bl_info = {
     "name" : "Cut Faces",
     "author" : "Stanislav Blinov",
diff --git a/mesh_tools/mesh_edges_length.py b/mesh_tools/mesh_edges_length.py
index ee9ae15b..b4e91be0 100644
--- a/mesh_tools/mesh_edges_length.py
+++ b/mesh_tools/mesh_edges_length.py
@@ -1,4 +1,6 @@
-# gpl author: Giuseppe De Marco [BlenderLab] inspired by NirenYang
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Author: Giuseppe De Marco [BlenderLab] inspired by NirenYang
 
 bl_info = {
     "name": "Set edges length",
diff --git a/power_sequencer/__init__.py b/power_sequencer/__init__.py
index 8d2c84db..c646da7c 100755
--- a/power_sequencer/__init__.py
+++ b/power_sequencer/__init__.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 from typing import List, Tuple, Type
 
 import bpy
diff --git a/power_sequencer/addon_preferences.py b/power_sequencer/addon_preferences.py
index 014f63dd..4220e89c 100644
--- a/power_sequencer/addon_preferences.py
+++ b/power_sequencer/addon_preferences.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 """
 Add-on preferences and interface in the Blender preferences window.
 """
diff --git a/power_sequencer/addon_properties.py b/power_sequencer/addon_properties.py
index 45c5bc20..575a3954 100644
--- a/power_sequencer/addon_properties.py
+++ b/power_sequencer/addon_properties.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 
diff --git a/power_sequencer/handlers.py b/power_sequencer/handlers.py
index b960662f..d9c107da 100644
--- a/power_sequencer/handlers.py
+++ b/power_sequencer/handlers.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from bpy.app.handlers import persistent
 
diff --git a/power_sequencer/operators/__init__.py b/power_sequencer/operators/__init__.py
index 406c8635..b1222a18 100755
--- a/power_sequencer/operators/__init__.py
+++ b/power_sequencer/operators/__init__.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import importlib
 import os
 
diff --git a/power_sequencer/operators/channel_offset.py b/power_sequencer/operators/channel_offset.py
index 48305c4b..b7569afa 100644
--- a/power_sequencer/operators/channel_offset.py
+++ b/power_sequencer/operators/channel_offset.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 from operator import attrgetter
 
 import bpy
diff --git a/power_sequencer/operators/concatenate_strips.py b/power_sequencer/operators/concatenate_strips.py
index d9119124..32f5f59b 100644
--- a/power_sequencer/operators/concatenate_strips.py
+++ b/power_sequencer/operators/concatenate_strips.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/copy_selected_sequences.py b/power_sequencer/operators/copy_selected_sequences.py
index e7bc7384..643ecb33 100644
--- a/power_sequencer/operators/copy_selected_sequences.py
+++ b/power_sequencer/operators/copy_selected_sequences.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/crossfade_add.py b/power_sequencer/operators/crossfade_add.py
index d4ffbe02..73644c80 100644
--- a/power_sequencer/operators/crossfade_add.py
+++ b/power_sequencer/operators/crossfade_add.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import find_sequences_after
diff --git a/power_sequencer/operators/crossfade_edit.py b/power_sequencer/operators/crossfade_edit.py
index dd5ff822..0e330e10 100644
--- a/power_sequencer/operators/crossfade_edit.py
+++ b/power_sequencer/operators/crossfade_edit.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.global_settings import SequenceTypes
diff --git a/power_sequencer/operators/cut_strips_under_cursor.py b/power_sequencer/operators/cut_strips_under_cursor.py
index 3b54a17b..4a66a782 100644
--- a/power_sequencer/operators/cut_strips_under_cursor.py
+++ b/power_sequencer/operators/cut_strips_under_cursor.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/delete_direct.py b/power_sequencer/operators/delete_direct.py
index 4c6e4d2d..bda5face 100644
--- a/power_sequencer/operators/delete_direct.py
+++ b/power_sequencer/operators/delete_direct.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_mouse_frame_and_channel
diff --git a/power_sequencer/operators/deselect_all_left_or_right.py b/power_sequencer/operators/deselect_all_left_or_right.py
index e3c5b888..6769d173 100644
--- a/power_sequencer/operators/deselect_all_left_or_right.py
+++ b/power_sequencer/operators/deselect_all_left_or_right.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/deselect_handles_and_grab.py b/power_sequencer/operators/deselect_handles_and_grab.py
index 20bfd426..468baf8b 100644
--- a/power_sequencer/operators/deselect_handles_and_grab.py
+++ b/power_sequencer/operators/deselect_handles_and_grab.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/duplicate_move.py b/power_sequencer/operators/duplicate_move.py
index 6d13b1d0..32c62a56 100644
--- a/power_sequencer/operators/duplicate_move.py
+++ b/power_sequencer/operators/duplicate_move.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_mouse_frame_and_channel
diff --git a/power_sequencer/operators/expand_to_surrounding_cuts.py b/power_sequencer/operators/expand_to_surrounding_cuts.py
index 53de8bf7..7129e42d 100644
--- a/power_sequencer/operators/expand_to_surrounding_cuts.py
+++ b/power_sequencer/operators/expand_to_surrounding_cuts.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import slice_selection
diff --git a/power_sequencer/operators/fade_add.py b/power_sequencer/operators/fade_add.py
index 11ef5b3c..39fe18a9 100644
--- a/power_sequencer/operators/fade_add.py
+++ b/power_sequencer/operators/fade_add.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from mathutils import Vector
 from math import floor
diff --git a/power_sequencer/operators/fade_clear.py b/power_sequencer/operators/fade_clear.py
index 02516633..c74b27cf 100644
--- a/power_sequencer/operators/fade_clear.py
+++ b/power_sequencer/operators/fade_clear.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/gap_remove.py b/power_sequencer/operators/gap_remove.py
index 825bfc0d..7f2ec5ae 100644
--- a/power_sequencer/operators/gap_remove.py
+++ b/power_sequencer/operators/gap_remove.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/grab.py b/power_sequencer/operators/grab.py
index 036a1493..de53d2a4 100644
--- a/power_sequencer/operators/grab.py
+++ b/power_sequencer/operators/grab.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_mouse_frame_and_channel
diff --git a/power_sequencer/operators/grab_closest_handle_or_cut.py b/power_sequencer/operators/grab_closest_handle_or_cut.py
index d9cc3681..55440b95 100644
--- a/power_sequencer/operators/grab_closest_handle_or_cut.py
+++ b/power_sequencer/operators/grab_closest_handle_or_cut.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 """
 Selects and grabs the strip handle or cut closest to the mouse cursor.
 Hover near a cut and use this operator to slide it.
diff --git a/power_sequencer/operators/grab_sequence_handles.py b/power_sequencer/operators/grab_sequence_handles.py
index 7780b4d2..ecbe8c4b 100644
--- a/power_sequencer/operators/grab_sequence_handles.py
+++ b/power_sequencer/operators/grab_sequence_handles.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.global_settings import SequenceTypes
diff --git a/power_sequencer/operators/import_local_footage.py b/power_sequencer/operators/import_local_footage.py
index 1b3a7ea6..8612210a 100644
--- a/power_sequencer/operators/import_local_footage.py
+++ b/power_sequencer/operators/import_local_footage.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import json
 import os
 import re
diff --git a/power_sequencer/operators/jump_time_offset.py b/power_sequencer/operators/jump_time_offset.py
index 1249c7c8..ee9b1f9b 100644
--- a/power_sequencer/operators/jump_time_offset.py
+++ b/power_sequencer/operators/jump_time_offset.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import convert_duration_to_frames
diff --git a/power_sequencer/operators/jump_to_cut.py b/power_sequencer/operators/jump_to_cut.py
index aff4a01c..add0dab9 100644
--- a/power_sequencer/operators/jump_to_cut.py
+++ b/power_sequencer/operators/jump_to_cut.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/make_hold_frame.py b/power_sequencer/operators/make_hold_frame.py
index 22c2eecf..4c1f110d 100644
--- a/power_sequencer/operators/make_hold_frame.py
+++ b/power_sequencer/operators/make_hold_frame.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 import operator
 
diff --git a/power_sequencer/operators/marker_delete_closest.py b/power_sequencer/operators/marker_delete_closest.py
index 6c71759f..a4756958 100644
--- a/power_sequencer/operators/marker_delete_closest.py
+++ b/power_sequencer/operators/marker_delete_closest.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/marker_delete_direct.py b/power_sequencer/operators/marker_delete_direct.py
index 5ebbbd74..efc8ba66 100644
--- a/power_sequencer/operators/marker_delete_direct.py
+++ b/power_sequencer/operators/marker_delete_direct.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/marker_snap_to_cursor.py b/power_sequencer/operators/marker_snap_to_cursor.py
index 0320454a..dbb3a6c7 100644
--- a/power_sequencer/operators/marker_snap_to_cursor.py
+++ b/power_sequencer/operators/marker_snap_to_cursor.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/markers_as_timecodes.py b/power_sequencer/operators/markers_as_timecodes.py
index 020bdfdd..52658838 100644
--- a/power_sequencer/operators/markers_as_timecodes.py
+++ b/power_sequencer/operators/markers_as_timecodes.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 import datetime as dt
 
diff --git a/power_sequencer/operators/markers_create_from_selected.py b/power_sequencer/operators/markers_create_from_selected.py
index b826a8c1..bd346d84 100644
--- a/power_sequencer/operators/markers_create_from_selected.py
+++ b/power_sequencer/operators/markers_create_from_selected.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/markers_set_preview_in_between.py b/power_sequencer/operators/markers_set_preview_in_between.py
index 3d4ee5a2..60724312 100644
--- a/power_sequencer/operators/markers_set_preview_in_between.py
+++ b/power_sequencer/operators/markers_set_preview_in_between.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import find_neighboring_markers
diff --git a/power_sequencer/operators/markers_snap_matching_strips.py b/power_sequencer/operators/markers_snap_matching_strips.py
index 0487880e..da475eeb 100644
--- a/power_sequencer/operators/markers_snap_matching_strips.py
+++ b/power_sequencer/operators/markers_snap_matching_strips.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/meta_resize_to_content.py b/power_sequencer/operators/meta_resize_to_content.py
index b75c20cb..ed54ebca 100644
--- a/power_sequencer/operators/meta_resize_to_content.py
+++ b/power_sequencer/operators/meta_resize_to_content.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from .utils.functions import get_frame_range
 
diff --git a/power_sequencer/operators/meta_trim_content_to_bounds.py b/power_sequencer/operators/meta_trim_content_to_bounds.py
index af101235..11b48369 100644
--- a/power_sequencer/operators/meta_trim_content_to_bounds.py
+++ b/power_sequencer/operators/meta_trim_content_to_bounds.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from .utils.global_settings import SequenceTypes
 
diff --git a/power_sequencer/operators/meta_ungroup_and_trim.py b/power_sequencer/operators/meta_ungroup_and_trim.py
index ffcd2711..00c79cf4 100644
--- a/power_sequencer/operators/meta_ungroup_and_trim.py
+++ b/power_sequencer/operators/meta_ungroup_and_trim.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/mouse_toggle_mute.py b/power_sequencer/operators/mouse_toggle_mute.py
index 3b0ab96b..362b2e9d 100644
--- a/power_sequencer/operators/mouse_toggle_mute.py
+++ b/power_sequencer/operators/mouse_toggle_mute.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 """Toggle mute a sequence as you click on it"""
 import bpy
 from math import floor
diff --git a/power_sequencer/operators/mouse_trim_instantly.py b/power_sequencer/operators/mouse_trim_instantly.py
index 849b23e5..332053fc 100644
--- a/power_sequencer/operators/mouse_trim_instantly.py
+++ b/power_sequencer/operators/mouse_trim_instantly.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from math import floor
 
diff --git a/power_sequencer/operators/mouse_trim_modal.py b/power_sequencer/operators/mouse_trim_modal.py
index a6b69812..a138933b 100644
--- a/power_sequencer/operators/mouse_trim_modal.py
+++ b/power_sequencer/operators/mouse_trim_modal.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 import bgl
 import gpu
diff --git a/power_sequencer/operators/open_project_directory.py b/power_sequencer/operators/open_project_directory.py
index 8c721051..f32f2ac2 100644
--- a/power_sequencer/operators/open_project_directory.py
+++ b/power_sequencer/operators/open_project_directory.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 import os
 from platform import system
diff --git a/power_sequencer/operators/playback_speed_decrease.py b/power_sequencer/operators/playback_speed_decrease.py
index a6799927..a856ac4b 100644
--- a/power_sequencer/operators/playback_speed_decrease.py
+++ b/power_sequencer/operators/playback_speed_decrease.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/playback_speed_increase.py b/power_sequencer/operators/playback_speed_increase.py
index f03d9cea..7c2f2ad2 100644
--- a/power_sequencer/operators/playback_speed_increase.py
+++ b/power_sequencer/operators/playback_speed_increase.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/playback_speed_set.py b/power_sequencer/operators/playback_speed_set.py
index af1737c6..9f576247 100644
--- a/power_sequencer/operators/playback_speed_set.py
+++ b/power_sequencer/operators/playback_speed_set.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/preview_closest_cut.py b/power_sequencer/operators/preview_closest_cut.py
index ec1af0d2..312be788 100644
--- a/power_sequencer/operators/preview_closest_cut.py
+++ b/power_sequencer/operators/preview_closest_cut.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_frame_range
diff --git a/power_sequencer/operators/preview_to_selection.py b/power_sequencer/operators/preview_to_selection.py
index 956da506..ea6c0ed7 100644
--- a/power_sequencer/operators/preview_to_selection.py
+++ b/power_sequencer/operators/preview_to_selection.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_frame_range
diff --git a/power_sequencer/operators/render_apply_preset.py b/power_sequencer/operators/render_apply_preset.py
index 670d637a..dc3b0ed1 100644
--- a/power_sequencer/operators/render_apply_preset.py
+++ b/power_sequencer/operators/render_apply_preset.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 import os
 
diff --git a/power_sequencer/operators/render_presets/twitter_720p.py b/power_sequencer/operators/render_presets/twitter_720p.py
index 47f235c4..109090cc 100644
--- a/power_sequencer/operators/render_presets/twitter_720p.py
+++ b/power_sequencer/operators/render_presets/twitter_720p.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 if __name__ == "__main__":
     import bpy
 
diff --git a/power_sequencer/operators/render_presets/youtube_1080.py b/power_sequencer/operators/render_presets/youtube_1080.py
index 343e7081..5bf6e826 100644
--- a/power_sequencer/operators/render_presets/youtube_1080.py
+++ b/power_sequencer/operators/render_presets/youtube_1080.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 if __name__ == "__main__":
     import bpy
 
diff --git a/power_sequencer/operators/ripple_delete.py b/power_sequencer/operators/ripple_delete.py
index 929e468f..939da4e0 100644
--- a/power_sequencer/operators/ripple_delete.py
+++ b/power_sequencer/operators/ripple_delete.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_brief, doc_description, doc_idname, doc_name
diff --git a/power_sequencer/operators/save_direct.py b/power_sequencer/operators/save_direct.py
index cd181f2d..f41c3d4f 100644
--- a/power_sequencer/operators/save_direct.py
+++ b/power_sequencer/operators/save_direct.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/scene_create_from_selection.py b/power_sequencer/operators/scene_create_from_selection.py
index cd774d0d..206e385a 100644
--- a/power_sequencer/operators/scene_create_from_selection.py
+++ b/power_sequencer/operators/scene_create_from_selection.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/scene_cycle.py b/power_sequencer/operators/scene_cycle.py
index cedbd4d6..1be39ab9 100644
--- a/power_sequencer/operators/scene_cycle.py
+++ b/power_sequencer/operators/scene_cycle.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/scene_merge_from.py b/power_sequencer/operators/scene_merge_from.py
index 5c3f40b0..b411e039 100644
--- a/power_sequencer/operators/scene_merge_from.py
+++ b/power_sequencer/operators/scene_merge_from.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/scene_open_from_strip.py b/power_sequencer/operators/scene_open_from_strip.py
index db512a9d..0b992356 100644
--- a/power_sequencer/operators/scene_open_from_strip.py
+++ b/power_sequencer/operators/scene_open_from_strip.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/scene_rename_with_strip.py b/power_sequencer/operators/scene_rename_with_strip.py
index 91ca8204..8bc6432f 100644
--- a/power_sequencer/operators/scene_rename_with_strip.py
+++ b/power_sequencer/operators/scene_rename_with_strip.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/select_all_left_or_right.py b/power_sequencer/operators/select_all_left_or_right.py
index 01e35306..7d9087ee 100644
--- a/power_sequencer/operators/select_all_left_or_right.py
+++ b/power_sequencer/operators/select_all_left_or_right.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/select_closest_to_mouse.py b/power_sequencer/operators/select_closest_to_mouse.py
index 8a8b8bc6..f14bc309 100644
--- a/power_sequencer/operators/select_closest_to_mouse.py
+++ b/power_sequencer/operators/select_closest_to_mouse.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import find_strips_mouse
diff --git a/power_sequencer/operators/select_linked_effect.py b/power_sequencer/operators/select_linked_effect.py
index 8a863062..a63096f1 100644
--- a/power_sequencer/operators/select_linked_effect.py
+++ b/power_sequencer/operators/select_linked_effect.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import find_linked
diff --git a/power_sequencer/operators/select_linked_strips.py b/power_sequencer/operators/select_linked_strips.py
index f6d77bbb..5716d13d 100644
--- a/power_sequencer/operators/select_linked_strips.py
+++ b/power_sequencer/operators/select_linked_strips.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/select_related_strips.py b/power_sequencer/operators/select_related_strips.py
index 3accb616..0e442ebd 100644
--- a/power_sequencer/operators/select_related_strips.py
+++ b/power_sequencer/operators/select_related_strips.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.global_settings import SequenceTypes
diff --git a/power_sequencer/operators/select_strips_under_cursor.py b/power_sequencer/operators/select_strips_under_cursor.py
index 0cc13c32..a47d6e80 100644
--- a/power_sequencer/operators/select_strips_under_cursor.py
+++ b/power_sequencer/operators/select_strips_under_cursor.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_sequences_under_cursor
diff --git a/power_sequencer/operators/set_timeline_range.py b/power_sequencer/operators/set_timeline_range.py
index 4b652bb1..65a90f4d 100644
--- a/power_sequencer/operators/set_timeline_range.py
+++ b/power_sequencer/operators/set_timeline_range.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/snap.py b/power_sequencer/operators/snap.py
index 13d5e66e..793f5bd9 100644
--- a/power_sequencer/operators/snap.py
+++ b/power_sequencer/operators/snap.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_sequences_under_cursor
diff --git a/power_sequencer/operators/snap_selection.py b/power_sequencer/operators/snap_selection.py
index eb2851b5..38da4c17 100644
--- a/power_sequencer/operators/snap_selection.py
+++ b/power_sequencer/operators/snap_selection.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from .utils.functions import get_sequences_under_cursor, move_selection
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/space_sequences.py b/power_sequencer/operators/space_sequences.py
index 519c2218..ddb28dfe 100644
--- a/power_sequencer/operators/space_sequences.py
+++ b/power_sequencer/operators/space_sequences.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import convert_duration_to_frames
diff --git a/power_sequencer/operators/speed_remove_effect.py b/power_sequencer/operators/speed_remove_effect.py
index 2d835fb2..ae2a4d35 100644
--- a/power_sequencer/operators/speed_remove_effect.py
+++ b/power_sequencer/operators/speed_remove_effect.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/speed_up_movie_strip.py b/power_sequencer/operators/speed_up_movie_strip.py
index daa68b2b..c004e2fc 100644
--- a/power_sequencer/operators/speed_up_movie_strip.py
+++ b/power_sequencer/operators/speed_up_movie_strip.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from math import ceil
 
diff --git a/power_sequencer/operators/swap_strips.py b/power_sequencer/operators/swap_strips.py
index 00c45107..44537c43 100644
--- a/power_sequencer/operators/swap_strips.py
+++ b/power_sequencer/operators/swap_strips.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/toggle_selected_mute.py b/power_sequencer/operators/toggle_selected_mute.py
index 362a9bd4..3ee1a022 100644
--- a/power_sequencer/operators/toggle_selected_mute.py
+++ b/power_sequencer/operators/toggle_selected_mute.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
diff --git a/power_sequencer/operators/toggle_waveforms.py b/power_sequencer/operators/toggle_waveforms.py
index 9dac9179..3e064182 100644
--- a/power_sequencer/operators/toggle_waveforms.py
+++ b/power_sequencer/operators/toggle_waveforms.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.global_settings import SequenceTypes
diff --git a/power_sequencer/operators/transitions_remove.py b/power_sequencer/operators/transitions_remove.py
index 8aa9f55f..d1db0d74 100644
--- a/power_sequencer/operators/transitions_remove.py
+++ b/power_sequencer/operators/transitions_remove.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/trim_left_or_right_handles.py b/power_sequencer/operators/trim_left_or_right_handles.py
index bbbb8bd5..aea81610 100644
--- a/power_sequencer/operators/trim_left_or_right_handles.py
+++ b/power_sequencer/operators/trim_left_or_right_handles.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 from operator import attrgetter
 
 import bpy
diff --git a/power_sequencer/operators/trim_three_point_edit.py b/power_sequencer/operators/trim_three_point_edit.py
index c10ffc42..f174589e 100644
--- a/power_sequencer/operators/trim_three_point_edit.py
+++ b/power_sequencer/operators/trim_three_point_edit.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.functions import get_mouse_frame_and_channel
diff --git a/power_sequencer/operators/trim_to_surrounding_cuts.py b/power_sequencer/operators/trim_to_surrounding_cuts.py
index 15982393..ab5df939 100644
--- a/power_sequencer/operators/trim_to_surrounding_cuts.py
+++ b/power_sequencer/operators/trim_to_surrounding_cuts.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 """
 Find the two closest cuts, trims and deletes all strips above in the range but leaves some
 margin. Removes the newly formed gap.
diff --git a/power_sequencer/operators/utils/__init__.py b/power_sequencer/operators/utils/__init__.py
index 34d53626..71fca8c4 100644
--- a/power_sequencer/operators/utils/__init__.py
+++ b/power_sequencer/operators/utils/__init__.py
@@ -1,16 +1,4 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
diff --git a/power_sequencer/operators/utils/doc.py b/power_sequencer/operators/utils/doc.py
index 84ec923c..8bdae410 100644
--- a/power_sequencer/operators/utils/doc.py
+++ b/power_sequencer/operators/utils/doc.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 """
 Utilities to convert operator names and docstrings to human-readable text.
 Used to generate names for Blender's operator search, and to generate Power Sequencer's documentation.
diff --git a/power_sequencer/operators/utils/draw.py b/power_sequencer/operators/utils/draw.py
index 6c13e27f..5a156bea 100644
--- a/power_sequencer/operators/utils/draw.py
+++ b/power_sequencer/operators/utils/draw.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 """Drawing utilities. A list of functions to draw common elements"""
 # import bgl
 import blf
diff --git a/power_sequencer/operators/utils/functions.py b/power_sequencer/operators/utils/functions.py
index 021dfd54..0d5c9fcf 100644
--- a/power_sequencer/operators/utils/functions.py
+++ b/power_sequencer/operators/utils/functions.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 from math import floor, sqrt
 from operator import attrgetter
 
diff --git a/power_sequencer/operators/utils/global_settings.py b/power_sequencer/operators/utils/global_settings.py
index 34ffd369..a5c9756b 100644
--- a/power_sequencer/operators/utils/global_settings.py
+++ b/power_sequencer/operators/utils/global_settings.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 class ProjectSettings:
     RESOLUTION_X = 1920
     RESOLUTION_Y = 1080
diff --git a/power_sequencer/operators/utils/info_progress_bar.py b/power_sequencer/operators/utils/info_progress_bar.py
index 8e679d72..e645c762 100644
--- a/power_sequencer/operators/utils/info_progress_bar.py
+++ b/power_sequencer/operators/utils/info_progress_bar.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 
diff --git a/power_sequencer/operators/value_offset.py b/power_sequencer/operators/value_offset.py
index e876a1bd..919e8a43 100644
--- a/power_sequencer/operators/value_offset.py
+++ b/power_sequencer/operators/value_offset.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 from .utils.doc import doc_brief, doc_description, doc_idname, doc_name
diff --git a/power_sequencer/tools/__init__.py b/power_sequencer/tools/__init__.py
index 463c3762..e7ac0ddc 100644
--- a/power_sequencer/tools/__init__.py
+++ b/power_sequencer/tools/__init__.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import importlib
 import os
 
diff --git a/power_sequencer/tools/trim.py b/power_sequencer/tools/trim.py
index e6a54437..9c60b2d0 100644
--- a/power_sequencer/tools/trim.py
+++ b/power_sequencer/tools/trim.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from bpy.types import WorkSpaceTool
 
diff --git a/power_sequencer/ui/__init__.py b/power_sequencer/ui/__init__.py
index 7cabf4fa..9b5b5c6b 100644
--- a/power_sequencer/ui/__init__.py
+++ b/power_sequencer/ui/__init__.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from .menu_contextual import POWER_SEQUENCER_MT_contextual
 from .menu_toolbar import (
diff --git a/power_sequencer/ui/menu_contextual.py b/power_sequencer/ui/menu_contextual.py
index 632821c2..41628448 100644
--- a/power_sequencer/ui/menu_contextual.py
+++ b/power_sequencer/ui/menu_contextual.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 from ..operators.utils.global_settings import SequenceTypes
 
diff --git a/power_sequencer/ui/menu_toolbar.py b/power_sequencer/ui/menu_toolbar.py
index a00e26ec..4feb1ea7 100755
--- a/power_sequencer/ui/menu_toolbar.py
+++ b/power_sequencer/ui/menu_toolbar.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 
 
diff --git a/power_sequencer/utils/addon_auto_imports.py b/power_sequencer/utils/addon_auto_imports.py
index a1dea3a8..47f430b9 100644
--- a/power_sequencer/utils/addon_auto_imports.py
+++ b/power_sequencer/utils/addon_auto_imports.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import pkgutil
 import importlib
 
diff --git a/power_sequencer/utils/register_shortcuts.py b/power_sequencer/utils/register_shortcuts.py
index beb75778..f928f7ff 100644
--- a/power_sequencer/utils/register_shortcuts.py
+++ b/power_sequencer/utils/register_shortcuts.py
@@ -1,19 +1,8 @@
-#
-# Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
-#
+# SPDX-License-Identifier: GPL-3.0-or-later
+# Copyright 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
+
 # This file is part of Power Sequencer.
-#
-# Power Sequencer is free software: you can redistribute it and/or modify it under the terms of the
-# GNU General Public License as published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# Power Sequencer is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
-# without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License along with Power Sequencer. If
-# not, see <https://www.gnu.org/licenses/>.
-#
+
 import bpy
 import operator as op
 from .. import operators
diff --git a/rigify/metarigs/Animals/bird.py b/rigify/metarigs/Animals/bird.py
index 03508418..e1897202 100644
--- a/rigify/metarigs/Animals/bird.py
+++ b/rigify/metarigs/Animals/bird.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/metarigs/Animals/cat.py b/rigify/metarigs/Animals/cat.py
index 95e08183..a6fd40ab 100644
--- a/rigify/metarigs/Animals/cat.py
+++ b/rigify/metarigs/Animals/cat.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/metarigs/Animals/horse.py b/rigify/metarigs/Animals/horse.py
index 70cb721b..cd393c5c 100644
--- a/rigify/metarigs/Animals/horse.py
+++ b/rigify/metarigs/Animals/horse.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/metarigs/Animals/shark.py b/rigify/metarigs/Animals/shark.py
index 8b72a965..6559fb4a 100644
--- a/rigify/metarigs/Animals/shark.py
+++ b/rigify/metarigs/Animals/shark.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/metarigs/Animals/wolf.py b/rigify/metarigs/Animals/wolf.py
index e6573279..a2ade910 100644
--- a/rigify/metarigs/Animals/wolf.py
+++ b/rigify/metarigs/Animals/wolf.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 
 
diff --git a/rigify/metarigs/Basic/basic_human.py b/rigify/metarigs/Basic/basic_human.py
index 254379a4..57b2d236 100644
--- a/rigify/metarigs/Basic/basic_human.py
+++ b/rigify/metarigs/Basic/basic_human.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/metarigs/Basic/basic_quadruped.py b/rigify/metarigs/Basic/basic_quadruped.py
index bfb73075..5575e8c4 100644
--- a/rigify/metarigs/Basic/basic_quadruped.py
+++ b/rigify/metarigs/Basic/basic_quadruped.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/metarigs/human.py b/rigify/metarigs/human.py
index 6b7a8daa..75a089ab 100644
--- a/rigify/metarigs/human.py
+++ b/rigify/metarigs/human.py
@@ -1,5 +1,6 @@
-import bpy
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+import bpy
 
 from mathutils import Color
 
diff --git a/rigify/rigs/experimental/super_chain.py b/rigify/rigs/experimental/super_chain.py
index c0a0f09e..8a51a938 100644
--- a/rigify/rigs/experimental/super_chain.py
+++ b/rigify/rigs/experimental/super_chain.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 from mathutils import Vector
 from ...utils import copy_bone, put_bone, org, align_bone_y_axis, align_bone_x_axis, align_bone_z_axis
diff --git a/rigify/rigs/faces/super_face.py b/rigify/rigs/faces/super_face.py
index 32d013a7..4d062aaf 100644
--- a/rigify/rigs/faces/super_face.py
+++ b/rigify/rigs/faces/super_face.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy, re
 from   mathutils      import Vector
 from   ...utils       import copy_bone, flip_bone
diff --git a/rigify/rigs/limbs/limb_utils.py b/rigify/rigs/limbs/limb_utils.py
index 609da256..b60e865a 100644
--- a/rigify/rigs/limbs/limb_utils.py
+++ b/rigify/rigs/limbs/limb_utils.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy, re
 from mathutils import Vector
 from ...utils import org, strip_org, make_mechanism_name, make_deformer_name
diff --git a/rigify/rigs/utils.py b/rigify/rigs/utils.py
index 89873ca4..cbc53e3a 100644
--- a/rigify/rigs/utils.py
+++ b/rigify/rigs/utils.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from ..utils.rig import connected_children_names
 from ..utils.naming import strip_mch, strip_org, make_mechanism_name
 import re
diff --git a/rigify/rigs/widgets.py b/rigify/rigs/widgets.py
index 0c434593..acafe750 100644
--- a/rigify/rigs/widgets.py
+++ b/rigify/rigs/widgets.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 from mathutils import Matrix
 from ..utils.widgets import create_widget, widget_generator
 
diff --git a/rigify/rot_mode.py b/rigify/rot_mode.py
index 59a233cb..a395ec6e 100644
--- a/rigify/rot_mode.py
+++ b/rigify/rot_mode.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 '''
 Quat/Euler Rotation Mode Converter v0.1
 
diff --git a/rigify/utils/__init__.py b/rigify/utils/__init__.py
index f2444d1c..8a2dee1d 100644
--- a/rigify/utils/__init__.py
+++ b/rigify/utils/__init__.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 # These forwarding imports are for backwards compatibility with legacy code
 # that expects a single utils.py file. New code should import directly from
 # the modules that contain the utilities. Also, don't add more imports here.
diff --git a/rigify/utils/components.py b/rigify/utils/components.py
index 5c1ebcb6..c1d01c90 100644
--- a/rigify/utils/components.py
+++ b/rigify/utils/components.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 
 from .naming import make_derived_name
diff --git a/rigify/utils/switch_parent.py b/rigify/utils/switch_parent.py
index ff5217b4..d4852c43 100644
--- a/rigify/utils/switch_parent.py
+++ b/rigify/utils/switch_parent.py
@@ -1,3 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
 import bpy
 
 import re
diff --git a/space_view3d_brush_menus/__init__.py b/space_view3d_brush_menus/__init__.py
index 9af3783c..e8b8c355 100644
--- a/space_view3d_brush_menus/__init__.py
+++ b/space_view3d_brush_menus/__init__.py
@@ -1,5 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
-# Modified by Meta-Androcto.
 
 """ Copyright 2011 GPL licence applies"""
 
diff --git a/space_view3d_brush_menus/brush_menu.py b/space_view3d_brush_menus/brush_menu.py
index ee7eff25..6a89dbf6 100644
--- a/space_view3d_brush_menus/brush_menu.py
+++ b/space_view3d_brush_menus/brush_menu.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import (
diff --git a/space_view3d_brush_menus/brushes.py b/space_view3d_brush_menus/brushes.py
index 0d70227d..dc9d5912 100644
--- a/space_view3d_brush_menus/brushes.py
+++ b/space_view3d_brush_menus/brushes.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import Menu
diff --git a/space_view3d_brush_menus/curve_menu.py b/space_view3d_brush_menus/curve_menu.py
index 5a836031..7ca509f3 100644
--- a/space_view3d_brush_menus/curve_menu.py
+++ b/space_view3d_brush_menus/curve_menu.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import (
diff --git a/space_view3d_brush_menus/dyntopo_menu.py b/space_view3d_brush_menus/dyntopo_menu.py
index 1a569787..df86a365 100644
--- a/space_view3d_brush_menus/dyntopo_menu.py
+++ b/space_view3d_brush_menus/dyntopo_menu.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import Menu
diff --git a/space_view3d_brush_menus/stroke_menu.py b/space_view3d_brush_menus/stroke_menu.py
index 8c5b0407..48174de8 100644
--- a/space_view3d_brush_menus/stroke_menu.py
+++ b/space_view3d_brush_menus/stroke_menu.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import Menu
diff --git a/space_view3d_brush_menus/symmetry_menu.py b/space_view3d_brush_menus/symmetry_menu.py
index 21e566d4..727dadd0 100644
--- a/space_view3d_brush_menus/symmetry_menu.py
+++ b/space_view3d_brush_menus/symmetry_menu.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import Menu
diff --git a/space_view3d_brush_menus/texture_menu.py b/space_view3d_brush_menus/texture_menu.py
index f5e0e960..01aec61d 100644
--- a/space_view3d_brush_menus/texture_menu.py
+++ b/space_view3d_brush_menus/texture_menu.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 from bpy.types import Menu
diff --git a/space_view3d_brush_menus/utils_core.py b/space_view3d_brush_menus/utils_core.py
index dc99ba0b..1bff1960 100644
--- a/space_view3d_brush_menus/utils_core.py
+++ b/space_view3d_brush_menus/utils_core.py
@@ -1,4 +1,4 @@
-# gpl author: Ryan Inch (Imaginer)
+# SPDX-License-Identifier: GPL-2.0-or-later
 
 import bpy
 
diff --git a/space_view3d_stored_views/core.py b/space_view3d_stored_views/core.py
index 5360b4bb..48452fad 100644
--- a/space_view3d_stored_views/core.py
+++ b/space_view3d_stored_views/core.py
@@ -1,5 +1,6 @@
-# gpl authors: nfloyd, Francesco Siddi
+# SPDX-License-Identifier: GPL-2.0-or-later
 
+# Authors: nfloyd, Francesco Siddi
 
 import logging
 module_logger = logging.getLogger(__name__)
diff --git a/space_view3d_stored_views/operators.py b/space_view3d_stored_views/operators.py
index 284e785c..137a711d 100644
--- a/space_view3d_stored_views/operators.py
+++ b/space_view3d_stored_views/operators.py
@@ -1,4 +1,6 @@
-# gpl authors: nfloyd, Francesco Siddi
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Authors: nfloyd, Francesco Siddi
 
 import bpy
 from bpy.props import IntProperty
diff --git a/space_view3d_stored_views/ui.py b/space_view3d_stored_views/ui.py
index 207f18c9..6d9e8d8a 100644
--- a/space_view3d_stored_views/ui.py
+++ b/space_view3d_stored_views/ui.py
@@ -1,4 +1,6 @@
-# gpl authors: nfloyd, Francesco Siddi
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+# Authors: nfloyd, Francesco Siddi
 
 import logging
 module_logger = logging.getLogger(__name__)