sentence: a partial list of such titles includes personal title , such as lord , knight , right honourable , indicating an earned or inherited rank or position within a formal power structure ; command rank , such as captain , sergeant , etc. , indicating likewise a very specific position in a command hierarchy , e.g. police rank or military rank ; an academic degree or professional designation such as phd , p.eng or m.d. , whether this be purely honorary or symbolic , or associated with credentials attesting to specific competence , learning , or skills ; labor union and club memberships ; persons allowed access to specific areas during special events , such as concerts and shows ; citizenship , as in the case of passport and birth certificate .