The output will be cards that are duplicates from decks you already mastered. Submit trade pile as comma separated list. For best results, please submit the source code of the mastered decks section of your website in as plain a form as possible, e.g. just <img>. The code will search for "deckmaster.gif" and "deck.png". If you use any different custom URL such as for first masteries, please let me know so I can edit that option into the code.