Metadata Encoding and Transmission Standard (METS) Official Web Site

METS News and Announcements

METS Editorial Board Endorses Extension Schemas for Use with METS

The METS schema is not prescriptive with regards to the metadata elements that those encoding METS documents may use to record descriptive or administrative metadata; those creating METS documents are free to use whatever metadata element sets they wish to record this information. They are also free to define their own encoding practices with regards to recording information conforming to an existing metadata schema. If an instititution needs to record Dublin Core metadata within its METS objects, for example, they may do so using whatever XML encoding practices they care to employ. This provides a great deal of flexibility in adapting METS to local practice.

This flexibility comes at a certain cost to interoperability, however. If each institution creating METS documents were to create its own XML Schema for Dublin Core, exchanging METS objects (and their associated Dublin Core metadata) would be a far more difficult task. Programmers writing software to process METS documents would have to proceed on the assumption that all descriptive and administrative metadata within any given METS document may have been encoded in an arbitrary and ideosyncratic manner.

In order to promote greater interoperability of descriptive and administrative metadata within the METS framework while retaining the flexibility to adapt METS to local needs, the METS Editorial Board may, on occasion, decide to endorse the use of a particular XML Schema as an extension schema for encoding descriptive or administrative metadata within METS. Institutions trying to decide on encoding practices for their METS documents are encouraged to give strong consideration to using Board-endorsed schema before developing their own schema implementation. In particular, institutions planning on exchanging METS documents with other institutions are strongly encouraged to use Board-endorsed schema whenever possible.

The METS Editorial Board has endorsed the following XML schema for use with the METS schema:

Library of Congress
Library of Congress Help Desk (June 15, 2003)