Something that came up in one of my last games was the issue of intimidation, ususally (and in this case specifically) pertaining to men checking women (eg playing zone).
The problem is a large guy on D, moving fast (and sometimes load) towards a female O player can often cause the female player to pull back, slow up or otherwise be "intimidated". This can have very real affect on the play.
I think we can all agree that playing agressive enough to cause a player, any player, to be intimidated is poor sportmanship & potentially dangerous, but are there any rules that govern this? Assume there is no contact & no pick, but that it definitely affects play.
Situations where this can apply include end zone plays (this ties into the discussion of the principle of verticality) where a bigger player in essence "forces" a smaller player not to jump for it for fear of collison or injury, overly aggressive marking & most relevant to my experience, attempting to block a catch. I'm mostly considering male-to-female situations, but any combo would be relevant.
The problem I see is that if tehre isn't any rules, it can be a "useful" tactic by a larger team as many (smart) players will back off to avoid injury & miss opportunities.
In our situation, the 2 teams talked & went on their merry way, but I'd love to see more clarity for next time.