Where can I find the regulatory guidance for the proper way for a commissioned officer to address an NCO?

The NCO"s have earned their titles and should be addressed by it, The use of first names is overly familiar, How would the officer like to be addressed by his first name by his subordinates

I can recall being called by my first name when I was a lieutenant; obviously trying to test me. I responded that my name was Lieutenant McAlister, but my friends called me sir. Seriously though, this officer is ill-disciplined not to mention rude. Step one is for the NCO to take him aside, and politely tell him that referring to NCOs by their first names is contrary to the customs and courtesies of the service, and undermines the sergeants authority. If that doesn't work, drop a dime to the CSM or company commander.

Back in the mid 60s at the Benning School for Boys I was a PFC and driver for BN XO. First thing in the morning when I would pull up to his residence, he would literally hop in the jeep and say Good Morning, Ronnie, and a fine day it is. In fact, he always called me Ronnie. I asked the BN SGM about it and he said that it was OK for the Senior to be familiar with the Junior, but not vice versa.
When just Sir wasn't appropriate, to use the third person. Served me well. I would think that is still good advice today.

AR 600-20

NCOs in the Army have 4 first names: Sergeant Major, First Sergeant, Sergeant, or Corporal

There is an order that states that you must address all military personnel by there rank and name regardless if they are above or below you. I can try to find the order SSG

When I was in Germany I had a Commander who was calling by my first name. I spoke to my 1SG and he nipped in the bud.

Your 1SG should talk to the Commander and inform him/her that NCO prefer being called by their rank. Regardless, if the Officers call each other by name they should respect us as they want to be respected. We are the Back Bone of the Army and we are more experienced than they are and should respect us as well.

I never seen an NCO calling another NCO by their first name we are not the same breed as them and we are professional as deserve to be respected as they want to be respected.

Not sure actual refs, but it's really about respect.
If it was a good officer, they called me by my nickname.
A term of endearment for me.
Bad officers I expected to be called by my rank as Sgt

If an officer can order you to your death, the least they can do is be professional to you. The military is not like working for Walmart.

When I first arrived in sunny South East Asia, I was met by a CPO who asked me my name. I was in civilian clothes. I said Jim: he said well FU Jim. I was his new CO. We called each other by first names and neither of us were upset by that. The only time I used his rank was during quarters.