Do you stand at parade rest for a NCO of another military branch?

PVT (Join to see)
Hell yes if your in the wrong! Remember your oath? Pretty simple!

It is appropriate to render the proper customs and courtesies for different branches, even of allied military forces.

It would do you well to study what the other branches rank insignia looks like, the Marines mirror ours fairly well. The Navy and Air Force may cause you some trouble, but as you study and interact with them you'll pick it up.

Officers are easy, they all wear the same brass. Allied officers not so much, so if you find yourself interacting with allies just make sure to study beforehand.

As for an Air Force NCO smoking an Army private... I would say no as it's likely to create friction for them. I've seen NCO's outside of a Soldiers formation get hemmed up for attempting to conduct corrective PT on a Soldier that isn't theirs, so I imagine the same may happen for someone outside your branch. That said, not showing the proper customs and courtesies can get you hemmed up as well.

Respect, doesn't matter the branch. As for "smoking a troop" that one is more difficult to remark upon. For instance, a Marine NCO might if the troop was the assigned Naval medic to that unit.

Most of the time in any join service area there is a certain amount of grace so to speak when working because of each branch's nuances of verbiage and customs and courtesies. Navy you don't call senior enlisted sir, but it is acceptable in the Air Force etc...

I have served in two branches and unless richly deserved I don't smoke anyone. I was stationed at a joint base(Navy/Air Force). After leaving the Navy to join the AF. Had an encounter with a Navy 3rd class who was grossly out of uniform standards. I pointed out to him his uniform failings(base-wide uniform inspections before SECDEF came in) told him he needed to correct them before his navy chief gave him a nasty ass-chewing. I pointed out that I was a prior-service navy and knew the uniform regulations at that time. He was junior and not standing in a proper military stance.

Yes, customs and courtesies but make sure that you know the ranks. Not all services ranks are the same. IE a Sergeant in the Air Force is not an E-5 but an E-4.

Yes, you should stand at parade rest no matter what branch that NCO is in. Live up to the Army values, and the word "smoke" is not a thing, it's "Corrective Training". Good luck!

I don't understand the question as it comes to simply providing a bit of respect, regardless of the branch of service you are engaged with. If someone approaches you of a higher "rank" then give them the courtesy you would expect others to provide to you. Also if you are being "smoked" as you put it...listen to what is said and if you believe they are in the wrong, run it up your chain of command. Overall it appears simple courtesy is missing from our society as a whole, but we should be able to keep it intact in our military community.

Your assumption that I know Air Force, Navy, or Marine Corps rank well enough to distinguish who is an NCO is flawed.

I don’t “smoke” people that I don’t “own”, but I would make on the spot corrections/give guidance to anyone and if they are subordinate in rank regardless of branch and I expect the appropriate courtesy just as I would give that same courtesy to to anyone in any branch senior to me. If it’s something that deserves torque applied to a service member because they need tightened up then that’s worthy enough of me seeking out that members supervisor and giving them a heads up and letting them handle it. I handle my Soldiers a certain way and other NCO’s from a different service might handle their’s differently. That’s Senior NCO perspective. When I was junior enlisted (E1-E4) if ANY NCO told me to do something I was moving. At the end of the day corrections make smarter and push-ups make you stronger.

You go to parade rest when ordered to do so.

An NCO from any branch out ranks you so you give respect where it's due, who smokes another brother for no reason? No way unless your in school or training.