A P Flag means any boat on the course side (OCS) of the start line at the starting signal must return, clear the start line and then restart. The I Flag means a boat which is OCS must round either end of the start line by coming back to the pre-start side and then restarting (the 'round the ends' rule). The Z Flag means a boat which is OCS in the minute leading up to the start or at the start itself is given a 20% scoring penalty. The Black Flag means a boat which is OCS in the minute leading up to the start or at the start itself is disqualified.