Postage stamp issued to honor a significant event, important person, or meaningful occasion; usually printed in limited quantities and not reprinted.

A stamp used by the post office to collect insufficient postage from the recipient when the sender has not paid the full amount.

A standard postage stamp issued for general and long-term use, typically featuring a small size and large circulation; contrasted with [[纪念邮票|紀念郵票|ji4 nian4 you2 piao4]] and [[特种邮票|特種郵票|te4 zhong3 you2 piao4]].

Postage stamps issued for a specific purpose or to commemorate a particular event, theme, or anniversary.

an exhibition of postage stamps or other philatelic materials