What Makes a Fighter British?

Michael Bisping is a British fighter...Bisping was born in Cyprus, which is a small island in the Eastern Mediterranean.  Bisping has lived in England since he was a child and trains in England.

Andre Winner is also a British fighter...Winner was born in Granada, which is even further from Great Britain than Cyprus, but he does live in England now and trains there...Maybe we have something here.

We can rule out being born in Great Britain as making a fighter British, since neither of them were technically born in Great Britain...is it the training?

Quinton Jackson is an American fighter...Jackson trains with Bisping in England...so training does not make you British...Maybe just saying you are British is the Key.

Marcus Davis is an American fighter...Davis pretends he is from Ireland...I guess it is more than just saying you are.

James Wilks is a British fighter...lives and trains in California...I am not seeing the connection here.

I am having problems with this whole British fighter game...You don't have to be born, train, or live anywhere near Great Britain to be British...You can't just claim you are British and have it work...so where is the title coming from?

Is it Citizenship that makes a fighter British?  If that were the case why would they go by the latter rather than the original?  If Quinton Jackson becomes an English citizen would he be an English fighter?

Is James Wilks working on a green card here for the past 15 years?  If he becomes an American Citizen does he forfeit winning TUF because he was fighting for the wrong team?