ackfuss-4.4.0/board/
ackfuss-4.4.0/help/e/
ackfuss-4.4.0/help/f/
ackfuss-4.4.0/help/h/
ackfuss-4.4.0/help/l/
ackfuss-4.4.0/help/n/
ackfuss-4.4.0/help/q/
ackfuss-4.4.0/help/s/
ackfuss-4.4.0/help/u/
ackfuss-4.4.0/help/v/
ackfuss-4.4.0/help/y/
ackfuss-4.4.0/help/z/
ackfuss-4.4.0/player/c/ 
INVIS

The invis command will make you invisible to anyone lower level, imms included.
All actions with your name will show as 'A Mystical Being', alluding to the
fact that you are an imm, but no revealing who.