Just to muddy the waters - The class rules for all three active IRSA international classes (IOM,10R, M) follow the same general format for their class rules, and give jurisdiction for measuring to the recognised national authority in each member country. The format is structured to reflect the Equipment Rules of Sailing (ERS). Section A for each of the Class Rules use BOLD type as a reference to defined terms in the ERS and all three classes use the term Official Measurer. I have found an anomaly - the issue is that the term Official Measurer is not a defined term in the ERS. The defined term in ERS is Certification Measurer. The wording is consistent with what we would intend for an official measurer but is not identified correctly. I have reported this discrepancy to the IRSA to verify and to follow up with the ICAs. From the ERS C.4.4 Certification Measurer A person appointed or recognised, by the MNA of the country where the control takes place, to carry out certification control and when the class rules permit, certification. An MNA may have delegated this responsibility. John