I'm losing my mind here trying to figure out what's wrong with the /follow command.

This is not working:
Code:
/follow [bar:1] Boohm; [bar:2] Bhoom; [bar:3] Bhoohm
WoW just says "Unknown unit"..
What's happening here? If I do the same but with targeting, it works.. but I get unacceptable problems with keeping targets if I use that.