The following slash commands are available:
/bcg show - Shows/Hides the main UI
/bcg options - Shows the Options Frame
/bcg X - executes a battlecry into a given channel

Where X is one of the following chat channels:
w = whisper**
s = say
p = party**
g = guild**
y = yell
bg = battleground**
r = raid**

** Not available in V.10 or lower