A pedant would point out that sponsorship is not prohibited or limited by the NOR – it is the display of advertising that is regulated. If your sponsor does not want a logo on sails/hull/gear then there is no problem., he can still write a cheque
Just to complicate matters the ISAF regulation has been changed. Category A and C no longer exist! Advertising either has to follow the prescriptions of ISAF or may be limited by the class or the event Any such limits would have to be in the NOR.
To make matters worse some parts of the reglation are confusing. For instance:
20.6.4 Boats/Boards, which are not an ISAF Class or are listed at Regulation 126.96.36.199,
participating in either in any event of such Class or in any of the events listed at
Regulation 188.8.131.52 (or added thereto) shall not display any Advertising nor be required to
display any Event Advertising without the prior written agreement of ISAF, either in
respect of a specific event, series of events or for a specific Class.
Naively, I read this as meaning that all boats that are not an ISAF class must get permission from ISAF to display advertising. However, I am assured, by eminent rules authorities, that this is not what is intended, and that unless classes limit advertising then boats may display advetising subject to ISAF regulations
As it is, for this event, unless the NOR is changed, the event sponsor cannot require competitors to display an event sponsors advert, and competitors may not display any advertising (except builders marks)