For referenc the non-relocation clause in Buffalo's contract. It has some very interesting parts. Read @1 for instance.

The agreement directly states that the Bills shall not:

(i) apply to the NFL for, or otherwise seek, approval to allow the Team to play any Games during the Non-Relocation Term anywhere other than the Stadium;
(ii) relocate, transfer or otherwise move the Team (or attempt to relocate, transfer or otherwise move the Team…) to a location other than the Stadium;
(iii) sell, assign or otherwise transfer the Team to any Person who, to the Bills’ knowledge, has an intention to relocate, transfer or otherwise move the Team during the Non-Relocation Term to a location other than the Stadium;
(iv) (A) entertain any offer or proposal to relocate the Team to a location other than the Stadium, (B) solicit an offer or proposal from any Person to enter into discussions regarding moving the Team to a location other than the Stadium, © enter into negotiations or agreements with third parties concerning the relocation of the Team to a location other than the Stadium, or (D) otherwise attempt to cause the playing of Games at a location other than the Stadium.

The Bills do, however, have the ability to explore relocation during the last five years of the lease (starting in 2050), so long as the relocation would not take place until after the conclusion of the agreement.

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