Questionable Tactic/Submission (For people who compete)

Alright...just a quick question for anybody who competes in any sort of grappling/submission wrestling of any sort out there (be it Judo, BJJ, etc.).

Is it legal in a match to lay your arm across your opponents throat from his guard/while mounted, etc? I know that there are some chokes where you can do something similar, but i was curious if just kind of "resting your arm" across his throat is legal or not in regulated matches, or if it's looked down upon or even illegal. I use it while sparring with buddies sometimes in the same manner as a crossface or putting your hand over his mouth or nose...mainly to disrupt his breathing and bother him. I know most MMA orgs don't look too kindly upon it, but it's legal in some, and illegal in others.

Note, I'm not trying to strangle him with the move, per se, but use it more as a distraction/dissausion tactic.

there is nothing illegal about puting your forearm on you opponents throat. I often shove my forearm into my foes throat, not b/c it will force a submission but to force them to usually give up and arm, open their guard etc etc.