Not true. As a CD I'm sure you're just forgot about these CL rules:

"The entrants AMA MAAC license must be permanently affixed to the upper right-hand wing surface at least 1" high prefixed with either ‘N' (USA) of C, CF (Canada)." - emphasis added

or in another spot:

"The contestant’s AMA number should appear as part of the scalelike license number on the upper right-hand wing. It may be preceded by “N’’ at the contestant’s option (emphasis added)."