Racing Rule 61.4 (a) was introduced in April 2001. At that time the International Sailing Federation (ISAF) introduced a rule (Regulation 21.2.1(h) in Appendix 2) that required all members of every crew in every race to be either a member of their national authority (US SAILING for sailors in the USA) or a member of a club or other organization affiliated to their national authority. The prescription to rule 64.1(a) is no longer needed because the ISAF has revised Regulation 21 and, in the revised version, Regulation 21.2.1(h) has been deleted. The revised regulation now requires such membership only for a limited number of major international championships. The revised regulation is part of the ISAF Eligibility Code and is now numbered Regulation 19.3. It can be found on the International Sailing Federation's web site.