Remove a card
Remove one copy, or a whole selection, from the card or from the collection view.
Open the card in your collection and remove it from its sheet. If you own several copies, lower the count instead of removing the card, so the remaining copies keep their condition and price paid.
From the collection view you can select several cards and remove them in one go. A removed card is gone from the collection total, the set completion and the badges that counted it; a card that leaves for a trade or a sale is meant to be removed, the same way.
Removing is not the same as marking a card for trade: a card on the Trade list stays in your collection and keeps its value.