Of course, Jorge won the BMF title in his UFC 244 (Nov. 2019) victory over Nate Diaz -- with UFC spending a TON of cash (around $50k) to get a special championship belt made.

Jorge hasn't fought since ... and now that he's finally getting back in the octagon, everyone wants to know if he's putting that belt on the line!

In fact, Usman -- the reigning UFC welterweight champ -- recently told us how BADLY he wants that belt.

But, bad news for Kamaru ... Dana says it ain't happening.

"It's not on the line," White tells TMZ Sports ... "Usman wants it to be on the line so bad, he will not stop texting me saying, 'I don't understand why this belt isn't on the line! This guy's running around saying he's the BMF champ!'"

"[Kamaru's] like, 'I wanna squash it all. [Masvidal's] not gonna win my title and I'm gonna take his BMF belt!'"

"Believe me," Dana says ... Usman has not stopped terrorizing me about this."

White says the BMF title fight was a "one and done" -- so, basically ... it's been retired.

There's a lot more ... Dana also tells us how he was able to put the Usman vs. Masvidal fight together so quickly after Gilbert Burns dropped out due to a positive COVID-19 test -- and if he ever considered using Colby Covington as a replacement fighter.

The whole thing goes down on July 11 at UFC 251 on Fight Island in Abu Dhabi ... and White tells us, he's so excited about the location, he's looking to buy a house there!

White says he's planning to return to "Fight Island" for more UFC events after the initial 4-event run in July ... and confirms it will be a regular location for the UFC for years to come.