The official Universal Postal Union designation for an air letter sheet. These sheets, with gummed flaps, are written on and folded into themselves to form their own envelope and are carried at less than the letter airmail rate. No enclosures are permitted.
A simple, lightweight letter sheet sold by the Post Office, pre-stamped for delivery worldwide. Sometimes, aerogrammes spot various commemorative or thematic illustrations.
a letter sent by air mail
a form with an imprinted stamp, and which is both writing paper and envelope
a letter for which you do not need an envelope - you simply write on it, then fold it up and send it
a lower cost version of an airmail letter
a postage paid letter which self seals into an envelope
Air letter sheets, usually carried for less than the normal airmail rates.
Postal stationery characterized by a single sheet which may be folded into an envelope, sealed and then sent at a rate less than the air mail letter rate. Postage is usually but not always imprinted. Also known as aerogram.