Nog is a slur used to describe Blacks in a derogatory way. Stands for "Nigger Out of Gas". Used by White police officers to describe Blacks who run out of gas and wait for the police to supply them some, which, supposedly, by law they have to do.
The word Nog is a racial slur that has been used historically to degrade and dehumanize blacks. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to blacks. If you are unsure about whether or not it is appropriate to use the word Nog, it is best to err on the side of caution and avoid using it in any situation.