pi is not an abbreviation. It is a letter of the Greek alphabet symbol that symbolises one particular ratio.
Prin. is not a universal abbreviation for any particular word. It could stand in for princess or principle or some other word beginning with prin. It depends on the context.
The "Mk" in Mk23 is an abbreviation for "mark", a designation for a version of a particular object.
SNA is the abbreviation of the stock company Snap-on Inc. Over the course of the past year, this particular stock has been on the rise, and is seeing a high in the market.
Prin. is not a universal abbreviation for any particular word. It could stand in for princess or principle or some other word beginning with prin. It depends on the context.
The abbreviation NPR does not stand for anything in particular, in an Isuzu. All it means is that the particular vehicle is part of the N-series from the manufacturer.
The initials for Arizona are AZ. All the states in the US have initials which are used as the abbreviation for a particular state.
a abbreviation is when a particular number is given and you have to add a letter to it . example : lunch + box means lunch box
When addressing a letter to a particular individual at a large company you might use the abbreviation "Att" or "Attn", eg. Att: Mr B Brown, or Attn: Mr B Brown. Either is acceptable.
As I remember, from the my drafting years back in the 70's it it is an abbreviation for particular type of screw thread. I recall that the c stands for Coarse. I checked Wikipedia. http://en.wikipedia.org/wiki/Unified_Thread_Standard
Formularythe Merck manual
Committee is often abbreviated in laws and other legal and governmental materials. The particular abbreviation varies according to the style guide used, but variants include Cmte, Cmtee, Comm, and, less commonly, Cttee.