Incidentally, in the United States Army (as far as I know, it's just the Army) there is a tradition in some units to give a challenge-response salute. For example, if you are a paratrooper in the 82nd, where this started as a way to further show themselves as more gung ho than 'legs', you'd call out "Airborne!" as you saluted an officer, and the officer would reply, "All the way!"
Other units in the Army do it too; the Rangers, obviously, go with "Lead the Way!" and 1st Cavalry goes with "Gary Owen!" and so on and so forth.
Well, Heinlein seemed to like this and it even shows up in the Paul Verhoeven movie as well, so I'm adopting it into Liberator culture as, "Liberators!" "Shoot to kill!" (because the average Imperial Stormtrooper doesn't.)