Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Postmark:

This text has been unreferenced on Wikipedia for a very long time. If you can't find a source, be bold and remove it!

"

While postmarks are applied almost universally by or under the authority of the official postal department, service, or authority in the United States it is possible to receive "a permit to apply your own postmark", called a Mailer's Postmark Permit,[8] and under certain conditions specified by the private express statutes in the United States, a privately carried letter may be cancelled with a private postmark.[9] Unofficial entities that issue artistamps may use postmark-like markings as well.[citation needed]