The portion of a Navy enlisted uniform that hangs from the back of the neck. (background) In the wooden navy it was fashionable for sailors to have long hair but it would get blown about by the winds and get stuck in the rigging or machinery. To counteract this, sailors at sea would braid their hair and dip it in tar (used to seal the boards on the ship). When ashore on liberty (as opposed to a longer leave where they would wash the tar out of the hair), they would cut a bib out of sack cloth and tie it around their neck to keep from getting tar on their one good shirt. The bib eventually became an official part of the enlisted uniform.