Quoted from slochar:
Nice, please add "board by DumbAss" somewhere on the silkscreen I think that would be hilarious.
Yes - board makers should always put their 'signature' (whatever it is - from a symbol, to just the name, initials, or something) on the board somewhere.
When I do mine, I put my little logo on it - both on silkscreen, and in a copper top or bottom layer. (Obviously, not the copper in an inner layer..)