Rematch clauses?

[Practical Goat]

I know McGregor and Diaz had a rematch clause.. Rose and Joanna also has one. What is it that determines a rematch clause? Is it the fighters decision, the UFCs or both? Seems strange how they are chosen, maybe I don't fully understand but I was watching 217 post-press conference the other day where Dillashaw is talking about how Garbrandt will have to start back at the bottom and work his way back up.. whereas other fighters get a rematch in a few months.

 

[Titleboxe]

I think you mean Bozoclauses, that's when you leave it up to Dana to make the final decisions.