RFC 2157 (rfc2157) - Page 3 of 49
Mapping between X
Alternative Format: Original Text Document
RFC 2157 X.400/MIME Body Mapping January 1998 1.1. Glossary The following terms are defined in this document: Body part Part of a message that has a unique type. This term comes from X.400; the corresponding term in MIME (RFC 2046) is limited to use in parts of a multipart message; the term "body" may correspond better. Content-type Type information indicating what the content of a body part actually is. This term comes from MIME; the corresponding X.400 term is "body part type". Mapping (noun): A description of how to transform an X.400 body part into a MIME body part, or how to transform a MIME body part into an X.400 body part. Equivalence A set of two mappings that taken together provide a lossless conversion between an X.400 body part and a MIME body part Encapsulation The process of wrapping something from one of the mail systems in such a way that it can be carried inside the other mail system. When encapsulating, it is not expected that the other mail system can make reasonable sense of the body part, but a gateway back into the first system will always be able to convert the body part without loss back to its original format. HARPOON encapsulation The encapsulating of a MIME body part by putting it inside an IA5 body with all headers and encoding intact. First described in RFC 1496 [HARPOON]. Tunneling What happens when one gateway encapsulates a message and sends it to another gateway that decapsulates it. The hope is that this will cause minimal damage to the message in transit. DISCUSSION At many points in this document, the author has found it useful to include material that explains part of the reasoning behind the specification. These sections all start with DISCUSSION: and continue to the next numbered section heading; they do not dictate any additional requirements on a gateway. Alvestrand Standards Track
