Here are entered works on art created collaboratively by using the postal service to transport a work in progress from one artist to another, and usually incorporating postal paraphernalia such as stamps, cancellations, etc. into the work.
Here are entered works both on cards sold by post offices with stamps already printed on them, usually mailable at rates lower than those for letters in envelopes, as well as on commercially printed cards, usually having a picture printed on one side, to which a stamp must be affixed for mailing.
Here are entered works on geographical areas used to determine postal rates or for administrative purposes within postal systems. Works on systems of numeric or alphanumeric codes used to expedite sorting and delivery of mail are entered under Postal codes.
