postmarked — an official mark stamped on letters and other mail, serving as a cancellation of the postage stamp and indicating the place, date, and sometimes time of sending or receipt.
dated — Dated things seem old-fashioned, although they may once have been fashionable or modern.
marked — strikingly noticeable; conspicuous: with marked success.
validated — to make valid; substantiate; confirm: Time validated our suspicions.
adjective franked
freed — enjoying personal rights or liberty, as a person who is not in slavery: a land of free people.
opened — not closed or barred at the time, as a doorway by a door, a window by a sash, or a gateway by a gate: to leave the windows open at night.
blunted — having an obtuse, thick, or dull edge or point; rounded; not sharp: a blunt pencil.
directed — proceeding in a straight line or by the shortest course; straight; undeviating; not oblique: a direct route.
