"P" is the luff
length of the mainsail, measured along the aft face of the mast from the top
of the boom to the highest point that the mainsail can be hoisted or black
band.
"E" is the foot length of the mainsail,
measured along the boom from the aft face of the mast to the outermost point
on the boom to which the main can be pulled or to the black band.
"I" is measured along
the front of mast from the genoa halyard to the main deck. The main deck is
where the deck would be if there were no deckhouse.
"J" is the base of the
foretriangle measured along the deck from the headstay pin to the front of the
mast.
