Advertising via sail numbers? 55

I can't believe any of the key stakeholders in this situation have not stepped in and brought this thread to a conclusion. 

My Aplogise for bad guess at sailmaker and it not being tape drive.
I fact if they had not won it would have been full house of total rubbish!

That's d4. It's a proprietary technology of one of the cloth manufacturers. It's a panelled sail with fibres laid out in directions and densities as specified by the sailmaker. It is laid up and supplied either as a single sheet or panels, not sure which, to the sailmaker who then gets taping and stitching.
Think of it as a kind of franchised non patent infringing technology for membrane sails that allows small sailmakers access to bigger technology, whilst allowing the cloth manufacturer to just press the button and make cloth, albeit semi bespoke cloth.

Originally posted by gordon1277 Oh Dear the fireball shown as the Blithfield barrel winner looks to have not very new tape drive sails from Alverbank I think. Me thinks FB are trying to close the door and the horse has bolted

I've always understood self certification to be in addition to measurement checking at major championships and a programme of oversight. You can imagine for wider spread international classes that in some places there might not be a measurer in your country. And if someones sail/mast/hull is going to fail to measure you want to know before they turn up and find out the weekend before the Worlds...