Classify your decks by game format

As you may have noticed, you can now indicate the game format your decks are built for. This way others can search for decks in a given format, and players know which decks match theirs and can challenge them to a balanced duel.

[I have tried to guess the format for the existing decks, but I have probably made mistakes, so please check your own decks and make sure they show the correct format.]