Permission to board

PTB is an abbreviation for "Permission to Board". Some crews require everyone, even crew members, to ask permission before they board a ship. This is often considered simply common courtesy and permission will be automatically granted. In other cases, there are reasons why even other crew members may not be welcome on a crew ship. For example when a new officer is being trained, they may not want others to see their mistakes. People who are making trade runs instead of pillages or are practicing navigation to memorize routes may want to avoid all battles. Also, sometimes you want a reduced number of people on the ship in order to increase the booty payout.