Delvers and Proxies vs Checklist Cards
What do you guys think about this? What is okay for each REL, using a proxy to denote a Delver of Secrets? Using two sets of Delvers? Do the sleeves used matter (solid color or designed that you can't see through)? Using non- MTG back cards, or non MTG cards altogether (ie using a Squirtle as a proxy)? What about using a plains (assuming there is no white in the deck) or an acetone-wiped card altered to be a Delver of Secrets, assuming the card is clearly labeled and recognizable as a Delver Proxy?
Some of these are pretty obvious *coughSquirtlecough* but some are not. I'm sure some higher REL tournaments are very strict but I've seen some interesting cards, some very heavily altered, in feature matches for modern or legacy tournaments.