A technical knockout or TKO differs from a true ten-second knockout; it usually occurs when a boxer is deemed unfit to continue and the referee ends the bout. This may be to protect a boxer who is being unduly punished by his opponent; or as a result of injury such as a bad cut, broken nose or jaw. Sometimes the boxer's corner, second, trainer, or manager may ask the referee to stop it, throw in the towel, or the boxer himself may retire on his own volition.
The referee is the only official who can declare a TKO, but he might consult the ring doctor for his opinion.
A technical knockout ends the bout, and results in a TKO win for the boxer's opponent (a TKO counts towards the "knockout" total in a boxer's fight record). This type of stoppage is also known as Referee Stops Contest (RSC) or Technical Count Out (TCO).