NIB is the acronym for a number of banks and boards, such as the National Irish Bank, or the National Irrigation Board. It is also the name of a song and has been ascribed the meaning "Nativity in Black."
In my primary schoodays we used dip pens. We had a pen with a nib fixed at the end, and we had to dip the nib into an inkwell after writing a few words ... From time to time the nib wore out and had to be replaced. Fountain pens also have nibs.