The IETF has released a fifth draft of XML Media Types. It includes an extension suffix for XML formats of "+xml", further develops the rules for charset parameters of XML types, and reflects the changing status of W3C specifications.

The appendix of the draft acknowledges the difficulty of processing XML through the existing MIME mechanisms:

In the ten years that MIME has existed, XML is the first generic data format that has seemed to justify special treatment, so it is hoped that no further suffixes will be necessary.

To handle this special case, the IETF draft defines basic types (text/xml, application/xml, text/xml-external-parsed-entity, application/xml-external-parsed-entity, and application/xml-dtd) and allows developers to create their own types, marked with the "+xml" suffix, to cover specific XML formats.

The modifications since the third edition previously covered by xmlhack include:

• the suffix sign has been changed to "+"
• arguments against a charset parameter of application/xml have been added to answer Rick Jelliffe's comment on XML-DEV have been added.
• references to XML Base, XLink and XPointer have been made non-normative.