honorifics

• the use of honorifics

These are called honorifics or terms of address.

Yes, it seems appropriate. Honorifics such as "Honorable" are usually reserved for elected officials (even a Precinct Chairman can be Honorable,) but officials of very high rank and responsibility can also be Honorable.

Honorifics can be tricky. You might be enlightened by checking with the web page of the Postmaster.

These are typically called titles in most situations. Honorifics is another term for them.