What regulation covers how to address a non commissioned officer?

Answer 1

In the US Army, AR 600-20, Command Policy, lists all ranks and their Titles of Address in Table 1-1.

Answer 2

The regulation that covers how to address a non-commissioned officer is typically covered in the respective branch's service regulations, such as Army Regulation 600-20 for the U.S. Army or Air Force Instruction 36-2618 for the U.S. Air Force. These regulations outline the proper forms of address and respect to be shown towards non-commissioned officers based on their rank and position within the military hierarchy. It is important for service members to follow these regulations to maintain military discipline and professionalism.