A Placard

1. A sheet of paper or cardboard with a written or printed announcement on one side for display in a public place.
2. (obsolete) A public proclamation; a manifesto or edict issued by authority.
3. (obsolete) Permission given by authority; a license.
4. (historical) An extra plate on the lower part of the breastplate or backplate of armour.
5. (historical) A kind of stomacher, often adorned with jewels, worn in the fifteenth century and later.
6. The woodwork and frame of the door of a closet etc.