NOC

Please, a definition for NOC as in reference to the night shift!!! As long as I've been working, I've not seen this abbreviation anywhere except here in AN. This one's driving me nuts!
A lot of other abbreviations come across here that are not standard in other places. It really detracts from the content of the post when it's a guess about the meaning.
If all you folk out there would go EASY on the abbreviations it will be greatly appreciated. Thank you for your anticipated cooperation.
WTFAYTA?

http://docs.docstoc.com/pdf/3480340/...abf040ca94.pdf

It means nocturnal. Move along.

NOC = night

DUH ... I'm thinking there's something big. As in N=? O=? C=? So simple & obvious! Thank you!