Having read all the ideas, here's a simple way for the NFL to regulate this.
#1 A firm mandate by the NFL (which would have to be voted in by the owners) is that the "spirit and intent" is that all 16 games are to be played competitively with "Winning" as the prime objective regardless if playoff positions have alredy been clinched. Again, this is just a "mission statement"but again the NFL is still somewhat of an "old boys club" and I think this simple change will have an impact.
#2 The NFL Commishioner is mandated to invoke significant fines to NFL teams that fail to comply with #1. The Commish (with input from the NFL office) will total discretion to invoke these fines based upon a judgement call. The initial fine will be $1 million ( a real amount that an NFL owner will not want to pay). This year I can only think that Colts in Week 16 & 17, Saints in Week 17 and Cards in Week 17 would have failed #1 (I'm not sure what exactly BB was trying to do vs Texans but I guess his mainline starters played enough. Cincy certainly started Palmer & Ocho until they were down 24+ points in the 2nd half). In practice, this hammer would come down only when elite skill position players (QB, WR, RB and maybe select key defensive personnel).
Anyway, I don't think that it would require much more than the above. A change in the "mission statement", coupled with a BIG HAMMER for non-compliance. I think that it is best to leave the standard for invoking #2 "open-ended" (its like Pornography, you know it when you see it).
So how badly do you punish teams who are "trying" out guys late in the season to see what they have in a guy when you could have been playing your "best guys"?Also, how would you punish the Lions?
Again, no one gives a hoot about the scrub teams who are playing musical chairs at QB. That is why if the NFL wants to change this all they have to do is the above.
Leave it in Goodell's discretion, don't touch the Lions, Rams as those teams that suck anyway and are simply trying to find their way. I would expect this to only be enforced against teams that have already clinched playoff slots as that is the only time that this issue creates an uproar. Another poster said that the NFL will never want to do this may be correct. But Goodell works for the NFL and works for the owners and has stated that he wants to evaluate this issue. Hence, I propose a way to do it that would work and not create havoc with other aspects of the game (draft picks, point handicaps, a selection committee a la the NCAA tournament, etc). Obviously, this would only be done if the NFL wants to address the issue. That is a self evident statemetn.