WBO stands for the World Boxing Organization. It is the fourth of the four main bodies that control professional boxing, alongside the WBA, WBC and IBF. It was set up in 1988 in Puerto Rico by people who had left the WBA, and for its first years the big American networks and magazines refused to take it seriously — they would not even list its champions. That changed in the late 1990s, and by 1998 it was treated as a real world title body; today a WBO belt counts, and a fighter needs it to be called undisputed. So if you read an older boxing book that sneers at the WBO, that is history, not how people talk now. Like the other three, it is written as three capital letters and said one by one, and it normally sits in front of a noun: the WBO title, the WBO champion, the WBO rankings.