I was curious... here I am, creating textures for a map that I am working on, and I came across a problem: I have no idea what XO stands for! I was wondering because I would very much like to put the full position names of Senior Officers on their doors, but it is proving to be quite difficult as I can't possibly imagine what XO means and I don't want to put simply "Commander" on the door

. Can anyone help me with this?