For years, all three of the sanctioning bodies (WBC, WBA, IBF) would strip a fighter if they tried to unify one of those belts with the WBO. Now all of a sudden, you can. When did they start doing this? I think when Hopkins beat DLH, it was the first time someone didn't get stripped.
Earliest I can think of is 1997 , Ricardo Lopez unified the WBC and WBO Minimumweight titles by stopping Alex Sanchez is 5 rounds .