yellow card

noun yellow cards

1. A yellow-coloured card, shown to a player (especially in association football) as a caution that he or she has committed a flagrant foul; a further such foul would result in a red card.
2. One of various yellow-colored cards used to verify the healthiness, vaccination status or other medical info of travelers.
3. UK A form to record safety concerns and adverse reactions to medicinal drugs.
4. attributive, often A card sent out by a travelling dance or theatre company to request temporary personnel from a local labor union. Some large modern dance companies, most large ballet companies, and most large theater companies also require union crews. These are called yellow card companies.
5. historical A yellow ticket.
6. historical A card given to British Army personnel during The Troubles.