Dead Letter is also colloqually applied to any set of instructions, especially a law, that has lost its authority without being formally abollished or repealed. Aphorism Critical legal studies Jurisprudence Law (principle) Legal research Letter versus Spirit List of legal abbreviations Legal code Natural justice Natural law Philosophy of law Religious law External links Wikibooks Wikiversity has more about this subject: School of Law Look up law on Wiktionary, the free dictionary. ...

Dead Letter Mail (also known as a Dead Letter) is mail that cannot be delivered to the addressee or returned to the sender. This is usually due to lack of compliance with postal regulations, an incomplete address and return address, or the inability to forward the mail when both correpondents move before the letter can be delivered. Largely based on the British model that emerged in the late eighteenth century, many countries developed similar systems for processing undeliverable mail. The term 'dead mail' is perhaps a misnomer, and several jurisdictions have opted for the use of the term 'undeliverable mail' as more clearly representing the status of the item whose transmission has been impeded. Being internal departments within postal administrations, little information about the Dead letter office or Undeliverable Mail Office function has ever been made public. A few journal articles and at least one recently published book (Canadian) dealing with this topic have appeared. The United States Postal Service started a dead letter office in 1825 to deal with undeliverable mail. ...

Classification as a dead letter is one of the few instances where postal personnel are allowed to open first-class correspondence, ostensibly to search for clues as to the letter's origin or destination. Countries must also set up regulations for the disposal of dead letters, particularly when they contain items of value. Surprisingly, some very valuable items have turned up in undeliverable mail, including a stolen painting by Marc Chagall which turned up in a United States Postal Service sorting center in Topeka, Kansas. [1] Marc Chagall as photographed in 1941 by Carl Van Vechten Marc Chagall (July 7, 1887 – March 28, 1985) was a Jewish Belarusian painter. ... A USPS truck in San Francisco A smaller truck used in suburban areas This article describes the United States Postal Service. ... Location in Kansas Founded  -Incorporated December 5, 1854 February 14, 1857  County Shawnee County Mayor Bill Bunten Area  - Total  - Water 147. ...

Partly due to the development of computerized mail merge systems, the amount of undeliverable mail is increasing at a fairly high rate as more correspondence is sent out with incomplete or improper addresses.

It is anticipated that with increased collection and study of the postal markings originating from such offices, the body of literature on this obscure topic will grow. Many countries, including Canada and the United States, have issued special labels for envelopes that have travelled through the dead letter office. Genuinely used examples are highly prized by collectors, alhtough mint labels, because they have no postage value, are often fairly common. A postal marking is any kind of annotation applied to a letter by a postal service. ...