Non-Disclosure?

Interesting.

I've always wondered how this works when a player moves from one team to another before both teams meet. I would think that most teams would compel a "new employee" to do everything in his abilities to help his new team win, including sharing strategies, patterns, etc. about his former team. I've just assumed this is part of the game...

Perhaps not? Are there non-disclosure agreements in the NFL? Are clauses written into contracts? Anyone have any insight on this?