- (metrology) Symbol for the teracoulomb, an SI unit of electric charge equal to 1012 coulombs.
- The ISO 3166-1 two-letter (alpha-2) code for Turks and Caicos Islands.
- (Internet, initialism) Topic closed. Used in Internet forums to announce that a topic thread is locked, indicating that no further replies are allowed in that topic thread.
- (electronics, initialism) Time counter.
- (electronics, abbreviation) thermocouple.
- (initialism) Traffic collision.
- Initialism of .
- Initialism of ., Turkish Republic.