Gary gave the right answers.

But to entlighten the reply I would like to explain the underlying criterium.

Pretty much the mossies will be regarded grandfathered (as they are now) as long as their Texel handicap rating is the same OR slower than that of the real F16's. Any mossie complying with the current mosquito class rules and adding a 17.5 sq. mtr. spinnaker will satisfy this Texel rating based grandfather criterium.

Wouter