The easiest would be C, but it is a known problem that although it's procedurally correct to fly a class flag over a signal flag to make it applicable only to that class, it has the potential to create confusion if other classes see the C flag but not the class flag over it. Again, really only an issue if the starting boat is near the gate (which happens all the time in our classes).

Anyway, there are a number of flags with specific meanings in the RRS. There are 26 letters in the alphabet. Pick one that isn't used for something in the RRS.

I agree, standardizing would help, especially since a lot of clubs still don't buy full flag sets and only maintain the bare minimum (or less).

Mike