Why? Because codenames are awesome!
Anyway, these aren't canon unless people start using them that way. I came up with them unless otherwise noted.
I'll be adding more, so if you'd like your character's resistance codename added, drop me a line!
Dadalus--Kingfisher (I lied...this one IS canon. See his profile.)
LFoe (Both: ~darthvengeance0325)
WillSgt. Pepper (Both: ~annarowlye)
RiaRoc (Both: ~minervagem)
BellatrixOrion (Both: ~mnemonides)