Slab
Slab or
jiffy reefing allows for the quick establishment of a
new tack and clew, while the halyard is partially lowered and then raised. One or two reefing lines passing through the sail's luff and leach reef cringles create a new tack and clew for the sail by pulling those points tight to the boom.
The holes in the middle of the sail are not tensioned. You can clean up the loose sail by lightly gathering and tying the sail with the mid cringles. Advise is not to tie these points to the boom. You can, in error, tear your sail should you forget to release these ties off the boom.