This results in the referee stopping the fight, and it is officially recorded as "RTD" (Retired) in boxing records, including those maintained by BoxRec.
In contrast, a technical knockout (TKO) may only be declared by the referee or ringside doctor, at any stage of the fight including rest periods.
In either case, an RTD still counts as a type of knockout, and is displayed as a stoppage result on a boxer's win/loss record.
One of the most famous RTD (corner retirement) stoppages in boxing history occurred on February 25, 1964, during the first fight of Muhammad Ali vs. Sonny Liston.
As a result, Ali was declared the winner by RTD and became the world heavyweight champion.