In November 2010, World Sailing (then ISAF) Council approved a completely rewritten Regulation 20, Advertising Code, and there have been minor changes since then. The Advertising Code (the Code) applies to all events organised in accordance with the Racing Rules of Sailing (RRS) and to all boats racing in these events; see RRS 6.1.
The Code can be downloaded from https://www.sailing.org/inside-world-sailing/rules-regulations/
The Code has significant implications for classes and handicapping and rating systems, for event organisers and for competitors. With minor exceptions, the Code applies only while boats are racing, as defined in the RRS.
The RYA has prescribed to the Code generally to the effect that, when advertising is subject to the prior approval of the RYA, such approval is automatically granted and that the RYA will not impose a fee on boats that choose to display advertising. The RYA Prescriptions can be found here and on pages 164-167 of the RYA version of the RRS.
It is vital that all classes state in their Class Rules whether advertising chosen by the owner or competitor is permitted, restricted or prohibited. If Class Rules are silent, advertising is permitted by default. References to Categories A or C advertising are not valid.
When Class Rules permit advertising, this must be approved. Approval is automatically granted to World Sailing Classes unless one of the exceptions applies; see World Sailing regulation 20.2.3. Some events or series of events that take place in more than one country require World Sailing approval; this may catch classes which have an international presence, such as Laser Europa Cup events. Most other advertising requires the approval of the relevant national authority.
Generally, the advertising rules for handicapping and rating systems are the same as for classes. However, if the applicable rules conflict, the more restrictive rules apply. Note the possible need for approval for international events as stated above.
The scope and limitations of event (sponsor) advertising are set out in regulation 20.4 and Table 1. Any requirement for boats to display event advertising must be stated in the notice of race for the event and, apart from bow numbers and backstay flags, the requirements will apply only while racing. The corollary is that boats may display other advertising, for example battle flags, when not racing.
When an organising authority provides boats or part thereof, all advertising on the supplied equipment is available to the organising authority.
It is now clear that an organising authority shall not charge different entry fees for boats that display advertising; see regulation 20.8.3.
Boat owners and competitors must ensure that any advertising on their boat complies with the Code generally and the Class Rules specifically. If the class or the handicapping or rating authority has not obtained approval for any permitted advertising, the Person in Charge of the boat must ensure that advertising on the boat is approved as required. This may be a problem if the relevant national authority is not the RYA.
A boat or a competitor may be protested for a breach of the Code by another boat or by a committee. The relevant regulation 20.9 is
20.9.1 Protests alleging a breach of this Code shall be governed by Part 5 of the RRS.
20.9.2 When, after finding the facts at a protest hearing, the protest committee decides that a boat and/or Competitor is in breach of any provision of this Code, it shall:
The RYA will endeavour to answer questions from class associations and from event organisers. Any questions must be by email addressed to email@example.com.
Questions from individuals can be answered only if the relevant class association has been unable to answer the question and if the individual is a RYA Personal Member.
 Note that all Codes are included in RRS 6. The previous rule numbers are no longer valid.