I think this contentious phrase may be being misused.
Anyone who has seen Roberto Duran/Pat Lawlor knows Duran did not retire on his stool, the ref stopped the fight. This was a TKO, otherwise the second Leonard fight must also be a RTD8 which we all know is bollocks!
WHATS THE DEFINITION OF "RETIRED"?
Thank U overhand_proofreader, correction made. 
There is nothing contentious about it.
A TKO is a fight stopped by the referee during the round while the clock is still running.
An RTD is a fight stopped by the referee between rounds while the clock is stopped.
This ruling is British (Who invented Boxing.) and has been around since before U were
a gleam in your pappy's eye.
Also;
If we are going to knit pick according to the rules, the correct verdict for Duran-Leonard
should have been a disqualification. (Refusing to fight.)
There is nothing contentious about it.
A TKO is a fight stopped by the referee during the round while the clock is still running.
An RTD is a fight stopped by the referee between rounds while the clock is stopped.
This ruling is British (Who invented Boxing.) and has been around since before U were
a gleam in your pappy's eye.
Also;
If we are going to knit pick according to the rules, the correct verdict for Duran-Leonard
should have been a disqualification. (Refusing to fight.)