A Couple of Bars: The Lieutenant

Boom-Boom Girl—Prostitute.

Butter Bar—A second lieutenant, particularly the college-minted kind who wasn't prior enlisted.

C-Ration—Technically, it was a Meal, Combat, Individual, but the name from World War II and Korea stuck even when the military came out with the new combat ration for Vietnam. A decade after Vietnam they were, in turn, replaced by the Meal, Ready-to-Eat (MRE). That new acronym gained traction and the C-Ration finally passed into lore and Hollywood scripts.

Charlie—Short for Victor Charlie, phonetic alphabet for Viet Cong.

Class As—The fugly Army Green Service Uniform that was the equivalent of a business suit. It was replaced by the blue, fuglier Army Service Uniform of today. Thankfully (just an opinion ... no hate please!) the Army is going back to uniforms based on the "pinks and greens" of World War II in 2020. Classy!

CO—Commanding officer.

Didi—To leave or go. A corruption of a Vietnamese word, đi.

Forward Observer—The soldier out in the field responsible for calling for and directing artillery fire onto a target.

Fruit Salad—Medals and service ribbons on the chest of the uniform.

In-Country—Vietnam in this case.

Jody—The mythical guy who was back in the States sleeping with your girl while you were in-country. Also gave his name to the cadence calls used while marching ("I don't know but I've been told, generals' balls are made of gold. Left, left, ... etc.").

LZ—Landing zone. Usually cleared with artillery fire before the helicopters came in if it was a combat assault but not always successfully.

Old Boots—Soldiers who've been in-country a while.

P-38—The tiny, hinged can opener in a Meal, Combat, Individual. Or, if you're going to call the food that instead of C-Ration, then specification MIL-O-20582A tells you to call this an Opener, Can, Hand, Folding.

RTO—Radiotelephone operator, the guy carrying 50+ pounds of gear so the forward observer can contact the artillery battery.

Slick—A Huey helicopter used for carrying troops on a combat assault. With only the M60s in the doors, they were sleeker than the gunships that had rocket pods, mini-guns, nose launchers for M49 grenades, and pretty much anything else someone could figure out how to attach and fire.

Top—An informal form of address for the first sergeant, the senior non-commissioned officer in a company/battery/troop.

And these days, maybe I'd better mention:

Call Collect—A process whereby you used a payphone (noun, archaic), told the operator (noun, archaic) your name, asked them to reverse the charges (verb, archaic) ... *smile*