I just got an email from a councilman's chief of staff--it's Cm. I found this post because I'm now looking for the abbreviation for Councilwoman!
The proper abbreviation for extension is "ext."
The proper abbreviation for kilohertz is kHz.
The proper abbreviation for Sunday is Sun.
The honorific would be The Honorable Councilman/woman John /Jane Doe, and the salutation is Dear Councilman/woman Doe.
The proper abbreviation for Registered Chemist is RCh.
The proper abbreviation title for an attorney is "Esq."
There is no proper abbreviation for the word global. It is often symbolized by a letter G in acronyms. As far as an abbreviation goes, many people use Gl., but this is in no way a proper abbreviation.
The accepted abbreviation is Depr.
there is no abbreviation
The proper abbreviation for the word "confirmed" is "conf."
Mr. is the abbreviation for the proper noun Mister, a title. Proper nouns are always capitalized, as well as the abbreviation for a proper noun.