"Who knows for how long?"
"Forever" is the length. It's probably no longer in UFC contracts, thanks to Randy Couture and all involved in the bravery of going up against the "machine."
Fighters put their health and the future of our lives on the line EVERY FIGHT, yet as "Independent Contractors" can't even make decisions on bettering their future outside the cage. Hell, they can't even make any decision inside the cage on their clothing to make them money the UFC can't steal. I guess being forced what to wear, along with anything else NOT in the UFC's financial gain, is fair.