A very handy thing when collaborating on a map is the ability to keep track of your own entities and those of your partner(s). You can set up your DoomEdit Windows shortcut so that each entity you create will have a specific prefix in its name.
For example:
“D:\Games\Doom 3\Doom3.exe” +set r_fullscreen 0 +editor +seta radiant_nameprefix nkd
Now when I create a light in DoomEdit the name given is: “nkd_light_1” instead of “light_1”.