The simple answer would be for any SL16 owner wanting to sail as F16 to measure their jib and modify it if it is oversize (shaving a few mm off the foot should be enough).
Exactly.
The F16 class rules don't need to specify this or that boat is "in" the class or not. If any boat shows up and fits within the formula (okay to have a shorter mast, etc), then it can sail as an "F16."
