Take Notice or Note well

This is a abbreviations of N.
N.B.- Take notice or Note well (Note Bene)
Nov. - Naval, Navigation
N. Hqs- Naval Headquarters.
N.A.M - Non Aligned Movement
N.E.C - National Economic
N.P.T - Nuclear Non-Proliferation Treaty.
N.T.P - Normal Temperature and Pressure.
N. P. C. - National Population Council
N.C.C -National Cadet Crops , National Computer Council, National