Check whether your deck is actually legal

You can now tag a deck with a format and check whether it's actually legal in that format, with a clear reason for anything that isn't: banned, outside the set pool, not legal in that format at all, too many copies, or a Commander singleton violation. If your deck is on Archidekt, it's checked live against the real decklist. Anything else, paste your decklist in once and it's saved to the deck so you can re-check it later without pasting it again.