Thank you Wouter - 4.2.4. on nation codes does address the concern I raised.

A few other small things...

Since the ISAF rules referred to in 4.2.6 require sail numbers on both a mainsail and spinnaker, is it your intention that the F16 rules also be interpreted as requiring numbering of a spinnaker, or should 4.2.6 be modified to refer specifically to the ISAF rule with respect to the mainsail only?

Also, I'm not clear on the rationale for including 4.2.8 in addition to 4.2.6. I understand that the former is compatible with ISAF, but don't understand why you would want to be even more prescriptive than the ISAF by including the latter.

I notice that you have not made any mention of the F16 identifier at the bottom near the leech that was in the earlier proposal. Do you still have any preference on this? I'm guessing that the reason for explicitly expressing the preference regarding the insignia at the top is because it relates to an issue specifically contained in the ISAF rules.

It did initially seem a little odd to me that you would require an F16 to carry a number that is explicitly assigned by the class, but not require it to actually identify itself as an F16. However, I am guessing that this may be to make life easier for say a Taipan sailor, who might sometimes sail F16 and sometimes standard Taipan without having to change sail markings.

BTW, I notice that the ISAF rule does actually require a class insignia above the nation code. Even if you are not going to require an F16 insignia (maybe for the reason above), if you wanted to maintain consistency with the ISAF you could perhaps require a class insignia, but allow this to be either an F16 insignia or a design sub-class insignia, i.e. must have either, rather than may have either.

I don't have a strong opinion on this, but just want to make sure that you had noted the difference between the rule as written and the ISAF rule.

Mark.