modular_aphelion/modules/custom_sprites/code/markings_editor.dm 
| /proc/custom_sprite_apply_region_results | Puts every region's drawing and base markings on a body, then redraws it once. |
|---|---|
| /proc/custom_style_marking_conflict | Returns the marking a region's rows already wear that keeps another off it: one of its exclusion group. The preview and saving set a region through set_zone_from_list(), which drops the second marking of a group, so the editor refuses it first. |