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Guidelines for the Generation of Message IDs and Similar Unique Identifiers

Document Type Expired Internet-Draft (usefor WG)
Expired & archived
Author Claus Andre Faerber
Last updated 1998-09-02
RFC stream Internet Engineering Task Force (IETF)
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state Expired
Consensus boilerplate Unknown
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


[RFC822] and [RFC1036] define so-called 'Message-IDs' that represent a unique identifier for email and netnews messages. A similar identifier is also used by [RFC2045] for the 'Content-ID' label. For each of these protocols, uniqueness of the identifiers generated is more or less essential. Unfortunately, the original Message-ID specification requires that the generator have an own, non-temporary full qualified domain name available, which does not allow hosts that are connected via dialup lines and get dynamically assigned IP addresses (and hostnames) to generate unique IDs offline. This memo provides recommendations for the generation of such IDs without risking non-uniqueness.


Claus Andre Faerber

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)