Starfleet Training Command

From Memory Alpha, the free Star Trek reference.

Starfleet Training Command (or STC) was an operating authority of Starfleet education of Starfleet Academy cadets.

In 2154, Commander Charles Tucker remembered that he kept getting himself into trouble at STC. (ENT: "Observer Effect")

In 2285, Starfleet Training Command was responsible for the Academy's Enterprise-class Mark IV simulator which tested cadets with the Kobayashi Maru scenario. (Star Trek II: The Wrath of Khan)

In "Observer Effect", Commander Tucker makes reference to "STC" and at no time does he use the words "Starfleet Training Command". It is mere speculation that he was refering to the same STC as the Starfleet Training Command that is written on the simulator door, where the term originated in Star Trek II: The Wrath of Khan.

The branches of Starfleet
United Earth: Command • Materiel Supply Command • Medical • Mission Control • Security • Section 31 • Training Command
United Federation of Planets: Administration • Administrative Operations • Advanced Technologies • Command • Communications • Control • Dental • Engineering Corps • Exploratory Division • Information • Inspector General • Intelligence • Internal Affairs • Judge Advocate General • Materiel Supply Command • Medical • Mission Operations • Operational Support Services • Operations • Orbital Operations • OSHC • Research and Development • Science • Section 31 • Security • Shipyards Operations • Stellar Imaging • Tactical • Training Command • Warp Technologies