Would you make a uniform correction on a member of another branch of service?

I'd probably phrase it as a question, instead of as a correction. If the answer was squirrelly. I'd educate myself on the service reg in question. If I was right to question the response, I'd inform the person next time I saw them.

Absolutely, active duty or veteran, guard, reserve, it doesn’t matter. We all should take pride in the service of our country regardless of our service branch.

Only if you know their regs as well or better then your own.

yes i hate seeing unbuttoned back pockets.

Yes, I was stationed at Kirtland AFB in the old Defense Nuclear and Special Weapons Agencies in a Joint slot and it was expected that senior NCOs would know the uniform regs for the joint services and do NCO things regardless of what the troops parent service was.
At that time I knew what rite was for each branch and took actions accordingly.
The Navy was the hardest to get used to because it seemed they had a multitude of authorized outfits depending on rank and duties for the day.

I would have to be very sure that I wasnt about to make a fool of myself for saying something. Something as universal as a haircut, shined shoes, or correct undershirt is easy enough; however, ribbons, devices, and anything more service related, I would need to do my research first.

If I was aware of the deficiency per their governing uniform regulation, or an overall uniform regulation, like those on certain joint FOBs and camps. I currently work with the Air Force, so I’ve had the opportunity to study their regs and will correct a deficiency on their uniform if their personnel do not do so first

There is nothing wrong with correcting an improperly worn, or slovenly looking Military Man, but NEVER do it in public, pull them off to the side and correct them. Shake their hand and wish them well.. then move on your way. You have done your part and will feel good about it..

It is every soldiers duty to make uniform corrections, you may not know the other branches uniform but you can ask them if they are correct in the wear of the uniform, the power of Google on the cell phone is awesome, research on what may not know in advance.

No. Each branch is targeted to differing missions. Admittedly over the previous decade creep has set in and mixed up the mission originazation. But as was found with the development of digicamo each service seeks to procure the best and most effective gear for its members and the services run the gamut. Marines want light loads and quickness, Soldiers want maximum protections and utility. Sailors don't need either except for groups such as the SeeBees so they empathize comfort and wearablity. And Airmen differ from job to job in what they want and require.