Any actual proof of Lambda on Aspis?

[Giannis K. Hoplite]

Lets not forget the 6th century Attic black figure that shows the letter A. Using letters on teh shields as emblems clearly was not a Spartan innovation, and whenever used we don't have to asume they were used universally. A few of the same letters in the front rank of the enemy could be used to identify them if there ever was such a problem.
Khairete
Giannis