Warrants, petty officers, and leading ratings

Warrant officers received Admiralty authority to practice specialist trades aboard ship rather than a Crown commission. That warrant gave them officer status without assigning the same duties as a commissioned officer. Petty officer came from the idea of a small or minor officer. The nickname "killick" for a leading rating comes from the distinctive anchor badge, while historical gunners, carpenters, and other specialists entered a commissioned ship through warrants tied to their posts.