That was my first assignment in the Army. No, it’s not some secret code. Just shorthand. We talked about the triangular organization of the Army here. Since there are tons of functionally identical organizations around the Army, it’s easier to give a unit a designation rather than a name. So what unit was this?
I was in the 1st Squad, 1st Platoon, Company A, 1st Battalion of the 27th Infantry, 3rd Brigade of the 25th Infantry Division (Light).
Now, we normally don’t spell it out in that much detail. Most folks in the business know that that the 1st Bn. of the 27th Infantry is part of the 25th ID. So when we play the old game of “where were you stationed?”, we just say, “Oh, I was with 1-27IN”. Plus, it’s not unusual to be shifted around quite a bit inside a company or battalion during a tour. I actually spent that whole tour in Hawaii in the first platoon, but spent time in each of the rifle squads, the weapons squad, and the platoon headquarters.
During my tour in Germany, I started out in C/1-6IN, spent time in each platoon and the headquarters platoon, was moved over to our Brigade HQ (1BDE, 1st AD), then loaned out to a sister battalion, A/7-6IN, part of the 3rd BDE.
A few designations for different types of unit:
AV or AVN- Aviation
FA-Field Artillery (as opposed to the now defunct Coast Artillery)
ADA- Air Defense Artillery
MI- Military Intelligence
MP- Military Police (you can’t spell WIMP without MP!)
QM- Quartermaster Corps
TC- Transportation Corps
If I left your branch/corps out, just let me know. This list is by no means exhaustive. I’m happy to add on.