I've heard Al Riveron explain it on various shows. Here is one tape of him explaining it... what is OK and what will get an ejection.
Not a fan of that idea... I actually like it when athletes use their celebrity to draw attention to the important issues of our time.
Now, If the NFL wants to take away a draft pick from Houston because of that ridiculous stunt with Mike Pence, I'd be all for it. That was a disgrace.