Well - I had several. I started as a 13A Cannoneer. Then a 13E - Artillery Fire Direction, later a 13F Fire Support. Findly at the end I was a 13Z then a 75Z - Personnel Sergeant.
I had skill identifiers of L for linguist and H for instructor.
I had secondary MOSs of 82C Surveyor and Supply 76Y. I had college courses in surveying but never worked in the trade. All I knew about supply was that they had stuff and if you were nice they would give you some. MAN CANNOT LIVE ON TO&E ALONE - HE MUST HAVE EXCESS.