For the BYOB editions, advertising would most likely be handled per RRS K 2.2:
Boats shall be required to display advertising chosen and supplied by the organizing authority.
While not set in stone yet, I would imagine this being limited to the front 25% of the hulls.
Mike
Appendix K (NOR Guide) is advisory, and is not considered part of the rules until they become an actual NOR. K.2.2 also has references to ISAF Reg 20 in the margin.
Advertising is controlled by ISAF Regulation 20 (RRS 80) and is part of the rules (definition of Rules, subsection b).