diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_armature.cc b/source/blender/editors/space_outliner/tree/tree_element_id_armature.cc
index 74057845346..16ba205ef1c 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_armature.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_armature.cc
@@ -32,7 +32,7 @@ void TreeElementIDArmature::expand(SpaceOutliner &space_outliner) const
   expand_animation_data(space_outliner, arm_.adt);
 
   if (arm_.edbo) {
-    expandEditBones(space_outliner);
+    expand_edit_bones(space_outliner);
   }
   else {
     /* do not extend Armature when we have posemode */
@@ -43,12 +43,12 @@ void TreeElementIDArmature::expand(SpaceOutliner &space_outliner) const
       /* pass */
     }
     else {
-      expandBones(space_outliner);
+      expand_bones(space_outliner);
     }
   }
 }
 
-void TreeElementIDArmature::expandEditBones(SpaceOutliner &space_outiner) const
+void TreeElementIDArmature::expand_edit_bones(SpaceOutliner &space_outiner) const
 {
   int a = 0;
   LISTBASE_FOREACH_INDEX (EditBone *, ebone, arm_.edbo, a) {
@@ -94,7 +94,7 @@ static void outliner_add_bone(SpaceOutliner *space_outliner,
   }
 }
 
-void TreeElementIDArmature::expandBones(SpaceOutliner &space_outliner) const
+void TreeElementIDArmature::expand_bones(SpaceOutliner &space_outliner) const
 {
   int a = 0;
   LISTBASE_FOREACH (Bone *, bone, &arm_.bonebase) {
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh b/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh
index 6b156a954c9..d311bba720a 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh
@@ -25,8 +25,8 @@ class TreeElementIDArmature final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandEditBones(SpaceOutliner &) const;
-  void expandBones(SpaceOutliner &) const;
+  void expand_edit_bones(SpaceOutliner &) const;
+  void expand_bones(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_curve.cc b/source/blender/editors/space_outliner/tree/tree_element_id_curve.cc
index 0acbfed22ea..f33ca514041 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_curve.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_curve.cc
@@ -25,10 +25,10 @@ void TreeElementIDCurve::expand(SpaceOutliner &space_outliner) const
 {
   expand_animation_data(space_outliner, curve_.adt);
 
-  expandMaterials(space_outliner);
+  expand_materials(space_outliner);
 }
 
-void TreeElementIDCurve::expandMaterials(SpaceOutliner &space_outliner) const
+void TreeElementIDCurve::expand_materials(SpaceOutliner &space_outliner) const
 {
   for (int a = 0; a < curve_.totcol; a++) {
     outliner_add_element(
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_curve.hh b/source/blender/editors/space_outliner/tree/tree_element_id_curve.hh
index 2a4da3bf9ef..cc2812c3f30 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_curve.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_curve.hh
@@ -21,7 +21,7 @@ class TreeElementIDCurve final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandMaterials(SpaceOutliner &) const;
+  void expand_materials(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.cc b/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.cc
index 1e2bf4a9212..fd95e80ddbd 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.cc
@@ -28,10 +28,10 @@ void TreeElementIDGPLegacy::expand(SpaceOutliner &space_outliner) const
 {
   expand_animation_data(space_outliner, gpd_.adt);
 
-  expandLayers(space_outliner);
+  expand_layers(space_outliner);
 }
 
-void TreeElementIDGPLegacy::expandLayers(SpaceOutliner &space_outliner) const
+void TreeElementIDGPLegacy::expand_layers(SpaceOutliner &space_outliner) const
 {
   int index = 0;
   LISTBASE_FOREACH_BACKWARD (bGPDlayer *, gpl, &gpd_.layers) {
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.hh b/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.hh
index 7ccd90c1035..1f09c7d91bd 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_gpencil_legacy.hh
@@ -21,7 +21,7 @@ class TreeElementIDGPLegacy final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandLayers(SpaceOutliner &) const;
+  void expand_layers(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.cc b/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.cc
index 8da3994719a..576d3f2398d 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.cc
@@ -28,10 +28,10 @@ void TreeElementIDLineStyle::expand(SpaceOutliner &space_outliner) const
 {
   expand_animation_data(space_outliner, linestyle_.adt);
 
-  expandTextures(space_outliner);
+  expand_textures(space_outliner);
 }
 
-void TreeElementIDLineStyle::expandTextures(SpaceOutliner &space_outliner) const
+void TreeElementIDLineStyle::expand_textures(SpaceOutliner &space_outliner) const
 {
   for (int a = 0; a < MAX_MTEX; a++) {
     if (linestyle_.mtex[a]) {
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.hh b/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.hh
index 9b6dbf8bc30..0e0bd3765f2 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_linestyle.hh
@@ -23,7 +23,7 @@ class TreeElementIDLineStyle final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandTextures(SpaceOutliner &) const;
+  void expand_textures(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_mesh.cc b/source/blender/editors/space_outliner/tree/tree_element_id_mesh.cc
index b2fa02f4337..73e5c4c2f72 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_mesh.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_mesh.cc
@@ -25,17 +25,17 @@ void TreeElementIDMesh::expand(SpaceOutliner &space_outliner) const
 {
   expand_animation_data(space_outliner, mesh_.adt);
 
-  expandKey(space_outliner);
-  expandMaterials(space_outliner);
+  expand_key(space_outliner);
+  expand_materials(space_outliner);
 }
 
-void TreeElementIDMesh::expandKey(SpaceOutliner &space_outliner) const
+void TreeElementIDMesh::expand_key(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, mesh_.key, &legacy_te_, TSE_SOME_ID, 0);
 }
 
-void TreeElementIDMesh::expandMaterials(SpaceOutliner &space_outliner) const
+void TreeElementIDMesh::expand_materials(SpaceOutliner &space_outliner) const
 {
   for (int a = 0; a < mesh_.totcol; a++) {
     outliner_add_element(
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh b/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh
index 59bf1767cfa..9a976f2bced 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh
@@ -21,8 +21,8 @@ class TreeElementIDMesh final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandKey(SpaceOutliner &) const;
-  void expandMaterials(SpaceOutliner &) const;
+  void expand_key(SpaceOutliner &) const;
+  void expand_materials(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_metaball.cc b/source/blender/editors/space_outliner/tree/tree_element_id_metaball.cc
index aeb3104e396..7c55f5b7a98 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_metaball.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_metaball.cc
@@ -25,10 +25,10 @@ void TreeElementIDMetaBall::expand(SpaceOutliner &space_outliner) const
 {
   expand_animation_data(space_outliner, metaball_.adt);
 
-  expandMaterials(space_outliner);
+  expand_materials(space_outliner);
 }
 
-void TreeElementIDMetaBall::expandMaterials(SpaceOutliner &space_outliner) const
+void TreeElementIDMetaBall::expand_materials(SpaceOutliner &space_outliner) const
 {
   for (int a = 0; a < metaball_.totcol; a++) {
     outliner_add_element(
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_metaball.hh b/source/blender/editors/space_outliner/tree/tree_element_id_metaball.hh
index d2b17e4c4e4..427928ec14f 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_metaball.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_metaball.hh
@@ -23,7 +23,7 @@ class TreeElementIDMetaBall final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandMaterials(SpaceOutliner &) const;
+  void expand_materials(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_object.cc b/source/blender/editors/space_outliner/tree/tree_element_id_object.cc
index 37d94a1ab72..d28031e7599 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_object.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_object.cc
@@ -40,24 +40,24 @@ void TreeElementIDObject::expand(SpaceOutliner &space_outliner) const
 
   expand_animation_data(space_outliner, object_.adt);
 
-  expandData(space_outliner);
-  expandPose(space_outliner);
-  expandMaterials(space_outliner);
-  expandConstraints(space_outliner);
-  expandModifiers(space_outliner);
-  expandGPencilModifiers(space_outliner);
-  expandGPencilEffects(space_outliner);
-  expandVertexGroups(space_outliner);
-  expandDuplicatedGroup(space_outliner);
+  expand_data(space_outliner);
+  expand_pose(space_outliner);
+  expand_materials(space_outliner);
+  expand_constraints(space_outliner);
+  expand_modifiers(space_outliner);
+  expand_gpencil_modifiers(space_outliner);
+  expand_gpencil_effects(space_outliner);
+  expand_vertex_groups(space_outliner);
+  expand_duplicated_group(space_outliner);
 }
 
-void TreeElementIDObject::expandData(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_data(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, object_.data, &legacy_te_, TSE_SOME_ID, 0);
 }
 
-void TreeElementIDObject::expandPose(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_pose(SpaceOutliner &space_outliner) const
 {
   if (!object_.pose) {
     return;
@@ -129,7 +129,7 @@ void TreeElementIDObject::expandPose(SpaceOutliner &space_outliner) const
   }
 }
 
-void TreeElementIDObject::expandMaterials(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_materials(SpaceOutliner &space_outliner) const
 {
   for (int a = 0; a < object_.totcol; a++) {
     outliner_add_element(
@@ -137,7 +137,7 @@ void TreeElementIDObject::expandMaterials(SpaceOutliner &space_outliner) const
   }
 }
 
-void TreeElementIDObject::expandConstraints(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_constraints(SpaceOutliner &space_outliner) const
 {
   if (BLI_listbase_is_empty(&object_.constraints)) {
     return;
@@ -156,7 +156,7 @@ void TreeElementIDObject::expandConstraints(SpaceOutliner &space_outliner) const
   }
 }
 
-void TreeElementIDObject::expandModifiers(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_modifiers(SpaceOutliner &space_outliner) const
 {
   if (BLI_listbase_is_empty(&object_.modifiers)) {
     return;
@@ -212,7 +212,7 @@ void TreeElementIDObject::expandModifiers(SpaceOutliner &space_outliner) const
   }
 }
 
-void TreeElementIDObject::expandGPencilModifiers(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_gpencil_modifiers(SpaceOutliner &space_outliner) const
 {
   if (BLI_listbase_is_empty(&object_.greasepencil_modifiers)) {
     return;
@@ -255,7 +255,7 @@ void TreeElementIDObject::expandGPencilModifiers(SpaceOutliner &space_outliner)
   }
 }
 
-void TreeElementIDObject::expandGPencilEffects(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_gpencil_effects(SpaceOutliner &space_outliner) const
 {
   if (BLI_listbase_is_empty(&object_.shader_fx)) {
     return;
@@ -282,7 +282,7 @@ void TreeElementIDObject::expandGPencilEffects(SpaceOutliner &space_outliner) co
   }
 }
 
-void TreeElementIDObject::expandVertexGroups(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_vertex_groups(SpaceOutliner &space_outliner) const
 {
   if (!ELEM(object_.type, OB_MESH, OB_GPENCIL_LEGACY, OB_LATTICE)) {
     return;
@@ -304,7 +304,7 @@ void TreeElementIDObject::expandVertexGroups(SpaceOutliner &space_outliner) cons
   }
 }
 
-void TreeElementIDObject::expandDuplicatedGroup(SpaceOutliner &space_outliner) const
+void TreeElementIDObject::expand_duplicated_group(SpaceOutliner &space_outliner) const
 {
   if (object_.instance_collection && (object_.transflag & OB_DUPLICOLLECTION)) {
     outliner_add_element(&space_outliner,
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_object.hh b/source/blender/editors/space_outliner/tree/tree_element_id_object.hh
index 7e5db814507..a2f6b9fd392 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_object.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_object.hh
@@ -21,15 +21,15 @@ class TreeElementIDObject final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandData(SpaceOutliner &) const;
-  void expandPose(SpaceOutliner &) const;
-  void expandMaterials(SpaceOutliner &) const;
-  void expandConstraints(SpaceOutliner &) const;
-  void expandModifiers(SpaceOutliner &) const;
-  void expandGPencilModifiers(SpaceOutliner &) const;
-  void expandGPencilEffects(SpaceOutliner &) const;
-  void expandVertexGroups(SpaceOutliner &) const;
-  void expandDuplicatedGroup(SpaceOutliner &) const;
+  void expand_data(SpaceOutliner &) const;
+  void expand_pose(SpaceOutliner &) const;
+  void expand_materials(SpaceOutliner &) const;
+  void expand_constraints(SpaceOutliner &) const;
+  void expand_modifiers(SpaceOutliner &) const;
+  void expand_gpencil_modifiers(SpaceOutliner &) const;
+  void expand_gpencil_effects(SpaceOutliner &) const;
+  void expand_vertex_groups(SpaceOutliner &) const;
+  void expand_duplicated_group(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_scene.cc b/source/blender/editors/space_outliner/tree/tree_element_id_scene.cc
index 203fe43bbd5..3f10150796b 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_scene.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_scene.cc
@@ -23,33 +23,33 @@ TreeElementIDScene::TreeElementIDScene(TreeElement &legacy_te, Scene &scene)
 
 void TreeElementIDScene::expand(SpaceOutliner &space_outliner) const
 {
-  expandViewLayers(space_outliner);
-  expandWorld(space_outliner);
-  expandCollections(space_outliner);
-  expandObjects(space_outliner);
+  expand_view_layers(space_outliner);
+  expand_world(space_outliner);
+  expand_collections(space_outliner);
+  expand_objects(space_outliner);
 
   expand_animation_data(space_outliner, scene_.adt);
 }
 
-void TreeElementIDScene::expandViewLayers(SpaceOutliner &space_outliner) const
+void TreeElementIDScene::expand_view_layers(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, &scene_, &legacy_te_, TSE_R_LAYER_BASE, 0);
 }
 
-void TreeElementIDScene::expandWorld(SpaceOutliner &space_outliner) const
+void TreeElementIDScene::expand_world(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, scene_.world, &legacy_te_, TSE_SOME_ID, 0);
 }
 
-void TreeElementIDScene::expandCollections(SpaceOutliner &space_outliner) const
+void TreeElementIDScene::expand_collections(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, &scene_, &legacy_te_, TSE_SCENE_COLLECTION_BASE, 0);
 }
 
-void TreeElementIDScene::expandObjects(SpaceOutliner &space_outliner) const
+void TreeElementIDScene::expand_objects(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, &scene_, &legacy_te_, TSE_SCENE_OBJECTS_BASE, 0);
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_scene.hh b/source/blender/editors/space_outliner/tree/tree_element_id_scene.hh
index 6a05ee52134..2abc5013616 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_scene.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_scene.hh
@@ -21,10 +21,10 @@ class TreeElementIDScene final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandViewLayers(SpaceOutliner &) const;
-  void expandWorld(SpaceOutliner &) const;
-  void expandCollections(SpaceOutliner &) const;
-  void expandObjects(SpaceOutliner &) const;
+  void expand_view_layers(SpaceOutliner &) const;
+  void expand_world(SpaceOutliner &) const;
+  void expand_collections(SpaceOutliner &) const;
+  void expand_objects(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_texture.cc b/source/blender/editors/space_outliner/tree/tree_element_id_texture.cc
index bebdcade921..0f319b0b5d1 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_texture.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_texture.cc
@@ -25,10 +25,10 @@ void TreeElementIDTexture::expand(SpaceOutliner &space_outliner) const
 {
   expand_animation_data(space_outliner, texture_.adt);
 
-  expandImage(space_outliner);
+  expand_image(space_outliner);
 }
 
-void TreeElementIDTexture::expandImage(SpaceOutliner &space_outliner) const
+void TreeElementIDTexture::expand_image(SpaceOutliner &space_outliner) const
 {
   outliner_add_element(
       &space_outliner, &legacy_te_.subtree, texture_.ima, &legacy_te_, TSE_SOME_ID, 0);
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_texture.hh b/source/blender/editors/space_outliner/tree/tree_element_id_texture.hh
index 15a96006f4c..b9b95e81eee 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_texture.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_texture.hh
@@ -21,7 +21,7 @@ class TreeElementIDTexture final : public TreeElementID {
   void expand(SpaceOutliner &) const override;
 
  private:
-  void expandImage(SpaceOutliner &) const;
+  void expand_image(SpaceOutliner &) const;
 };
 
 }  // namespace blender::ed::outliner