You can see on Vic's picture the black band on the boom. The inner edge of the band is supposed to be the maximum that the main clew is extended.

I think ... but don't know for sure ... the tape is Velcro One Wrap Tape hook/loop 1" with a on line price of ~ $6.90 for 15' roll

velco tape reference

I have the same outhaul shackle and it looks like his is pulled to the stop as does mine. His taper looks steeper than mine though (my taper carries further forward). This could be just the angle of the photo.

Refresh my memory, will the OD legal main pull all the way to max outhaul (shackle hits end of boom). Perhaps it is because I have a non-leagl main that was made to measure so it may be a bit longer in the foot.

The main on Rhapsody does not reach the black band. About 1/2" to reach it. It measures as class legal.

photo after high wind day with all the flattening that we could do ... the shackle in this case doesn't allow it to go further back than the photo shows. it is one of Norths new woven fabrics. 7+ oz and probably with next to no stretch.

this is a mickey moused main that started as a bolt rope luff for last years NA, where it too measured ok

Was converted to tides marine slugs this year and then had to be trimmed back a bit to allow for the sail track pushed out from the mast. It is full battened.

North seems to want to make the foot on these sails a bit long.