The link to the most recent US Sailing Appeals Supplement 2017-2020 can be found here
(Note: The link on the USS web-page is temporarily offline .. so use the link above until that gets updated).
Question is a very interesting discussion regarding Rules 19.1
Appeal regarding timeliness of flying the protest-flag, follows closely behind the recent Appeal discussing the timeliness of hailing "Protest". When read along with the other referenced US Appeals , , it puts together a cogent picture around these questions.
Also, I'd like to say that I really appreciate that the US Appeals Committee referenced Case 138
, Answer 3 in their concluding remarks at the end of US124. The more this idea gets reinforced, the more chance we have for it to sink-in and take-hold.
From the end of US124 ..
"..a boat that realizes at the time of an incident that she broke a rule and does not take her penalty not only risks having her penalty found to be invalid, she also breaks a recognized principle of sportsmanship that requires a boat that realizes she has broken a rule to promptly take a penalty (see Basic Principles, Sportsmanship and the Rules; Rule 2, Fair Sailing; and World Sailing Case 138, answer 3)."