It can be for a special accomplishment , a symbol of authority granted by taking an oath ( e.g. , police and fire ) . It may also be a sign of legitimate employment or student status , or as a simple means of identification . A badge is a device or accoutrement , 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 .