Are your sail letters and numbers legal?

Within the Racing Rules of Sailing is Appendix G – Identification on Sails in which Appendix G1.2(a)requires that letters and numbers be “clearly legible”.
• Clearly (adverb): without doubt; obviously.
• Legible (adjective): clear enough to read.
Sail letters and numbers not meeting this rule requirement is a protest-able issue, and Race Committees are under no obligation to score boats they cannot identify. Chris Clark, 2020 Bayview Mackinac Race Chair, offers this reminder for the offseason:
New technology in sail making is making boats faster and sails last longer; this is a good thing. Given that many of the new sails are dark or black, special attention must be paid to having contrasting sail numbers.
Daytime finishes are hard enough but add in night finishes, many times when the sails are lit from shore or the boat, the sail numbers are not visible, even if they are in a contrasting color.
Please have your sailmaker inspect your sails and make sure your sails have the strongest contrasting color possible on all sails. This may not be the same color on every sail. Additionally, please consider using reflective material as part of your main sail numbers. This increased visibility does not just make life easier on the Race Committee it insures you, the competitor, gets the correct finish time.

Very simply put. If we can’t identify you, we can’t finish you. It is in your best interest to help us help you.