CC
The proper abbreviation for extension is "ext."
The proper abbreviation for kilohertz is kHz.
The proper abbreviation for Sunday is Sun.
The proper abbreviation for Registered Chemist is RCh.
The proper abbreviation title for an attorney is "Esq."
The proper abbreviation to send someone a copy of a memo is 'cc:' (type in the person's name and if there is more than one person that gets a 'cc' (meaning carbon copy which is old style) then tick off each name it is suppose to go too.
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.
cc
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.