I know very little about boxing. What are the rules on clinching?

Yon clinch when someone you're fighting is vey aggressive. You try to stop there attack by holding them for a few seconds. Look at Wlad fights for instance. He will show you how to clinch and drain someone energy. It looked like Pavetkin haven't ate anything for a week after Wlad was done with him. He barely could stand on his feet when the announcer said their names.

It depends how often and the circumstances. Usually the ref will warn a fighter for constant clinching, however Floyd did enough to keep it unnoticed by the ref.

Thanks for the clarifications. I know almost nothing about boxing, but it really seemed to take the wind out of Manny's sails every time Floyd did that. It's amazing how quickly the fight went by!!

Yon clinch *there