Badge

A badge is a device or accessory, often containing the insignia of an organization, which is presented or displayed to indicate some feat of service, a special accomplishment, a symbol of authority granted by taking an oath (e.g., police and fire), a sign of legitimate employment or student status, or as a simple means of identification. They are also used in advertising, publicity, and for branding purposes. Police badges date back to medieval times when knights wore a coat of arms representing their allegiances and loyalty.