Hello John, Thank you for your reply. Most helpful. We had a great time at the Nationals, though were disappointed not to do better. Hardly surprising, though, as we haven't competed for 2 years! Like you, we thought that division along the luff of the main sail was the key but we couldn't make sense of the measurements by that method. In the end we found measurement guidance in a 1992 copy of the Handbook. It says: Measurement points shall be marked on the sail from the top cringle in a straight line to the leech. The head cringle shall be within the sail area and measurements shall be taken from the top bearing surface. The cross measurements shall be the distance from the leech measurement point as defined above, to the nearest point on the fore edge of the sail, including the bolt rope. By this measurement definition, our main sail is in class. Could the definitions be restored to the latest Rules document? In the current Rules document, section G2.2 CERTIFICATION section (a) states that the sales shall be certified in the tack by the measurer. I was confused by the lack of signiture on our new sails. Given that they are certified by the manufaturer in accordance with G2.2 (b), this does not seem to over-ride paragraph (a), so I would still expect the manufacturer's measurer to sign the tacks. Is this your reading? Thank you again for your help and advice. All teh best, Peter Murgatroyd (H9400 Rosie)