When you're using a box or stack containing lots of cards, the Filter option can be used to quickly find cards based on any text added to the front of a card.
Click the filter icon at the top of the stack and type a word or phase. Any cards in the current box or stack that have matching text on the front of the card will be filtered and displayed below. This includes any cards using the 'Full image' layout where matching text is added to the front of the card but not visible.
You can select, copy, move, tag, colour, sticker and delete cards when a filter is active.
Click the hide filter icon to remove an active filter.