Ahhh... nothing like the government to have to put a number on everything. In my business, film and video, if you are on location and need a clothes pin to hold a gel on a light you ask for a "C47" Story is it got the name when some company was itemizing expendables for a government job and that's the number the clothes pins got.
Of course in the grip and lighting world they got all sorts of fun names for gear... gobos, hi-hats, lollipops, stingers the list goes on and on. To learn the trade you have to learn a new language.
Big Mickey