Quoted from bepositive:No suggestion other than maybe a mail label with your name on board .
When I need board repairs that are above my skill level and I send them to a pro, I always use a key tag with my name, address, and phone number on it. I remove the metal bit, and put a zip tie through the loop of the keytag, and one of the holes on the board. That way, there's never a concern over whether or not a board is mine.
https://www.harborfreight.com/color-coded-key-rings-12-pc-69726.html