OH NO YOU DIDN'T!
Here at APS we encourage sportsman like conduct at all times so when that little booger fouls you at the line, reach for your APS Pop-Out Protest Flag and pull the small white tab with all the rage that fills you!! Then politely inform the offending party that he or she is being protested.
These assorted color nylon pockets can be easily secured to your boom or backstay. When you are finished, stuff the flag back inside and Velcro it shut for protection from the sun.
Dinghy size is 5.5 x 5.5 inches; keelboat size is 11.5 x 11.5 inches.