Postmark

The postmarks bore the initial of the particular post office or handling house it was sent from along with a separate time stamp.

[4][5] In Great Britain, the first postmark employed for the cancellation of the then new adhesive postage stamps was the Maltese Cross, so named because of its shape and appearance.

Postmarks on naval vessels during sensitive operations in wartime are sometimes "clean", showing less information than usual to prevent route of travel or other details from falling into enemy hands.

[6] The Pony Express used a variety of different postmarks on the mail it carried across the Western United States.

There are only 250 known examples of surviving Pony Express mail/postmarks in various collections today bearing one of more than a dozen different types of postmarks.

[8] A colour postmark is on the United States Postal Service-issued collectible envelope commemorating the 2004 inauguration of George W.

[11][better source needed] These include the so-called fancy cancels of the United States to modern machine postmarks.

[citation needed] An official example relating a numismatic item to postmarks occurred on April 13, 1976, when the U.S. issued a new two-dollar bill.

People could buy the bills at face value, add a first class stamp (at the time 13 cents), and have the combination postmarked to show they were the first day of issue.

[12] When the first universal postal system was started in the United Kingdom with its Penny Black, the postmark used red ink for contrast.

The majority of postmarks today are in black, with red (particularly in the United States with local post offices' handstamps) following, though sometimes they are in other colours.

Historically, postmarks, known as backstamps were also applied to the reverse side of a cover to confirm arrival at the post office on a specific date.

Neither should a postmark be confused with overprints generally, or pre-cancels (stamps that have been cancelled before the envelope or package to which they are affixed is submitted or deposited for acceptance into the mailstream, they most commonly have taken the form of a pre-printed city name on the stamp) specifically, which generally do not indicate a date.