This addon further divides the props in the prop spawn menu into sub-tabs based on their “group.” Groups are taken from square brackets () that are in front of category names.
You can assign aliases and combine groups. See the README.txt file.
OR GET 1.11 which fixes ordering not working for custom group aliases:
WARNING: This addon non-permanently modifies the existing spawnmenu, but a future Gmod update that significantly modifies the spawnmenu (unlikely) may break this addon in fantastic ways.
NOTICE: Spawn lists are indirectly handled by this addon, and if you have invested a lot of time into creating custom ones, making a backup is suggested. The “Empty” and “Delete” commands carry a risk.