noun
donor card
A card indicating one's intention regarding organ donation; used in medical and legal contexts.
運転免許証の裏に意思表示カードの欄があります。
There is a donor card section on the back of the driver's license.
A more explicit term for 'organ donor card', while 意思表示カード is a shorter, commonly used form.
Compound of 意思表示 (declaration of intention) and カード (card).