(last updated 2022-08-16)

MIME media type name: application

MIME subtype name: oebps-package+xml

Required parameters: None.

Optional parameters: None.

Encoding considerations: 8bit if UTF-8; binary if UTF-16.

   Package documents are in XML, represented either in UTF-8 or 
   UTF-16. When the package document is written in UTF-8, the file is 
   8bit compatible. When it is written in UTF-16, the binary 
   content-transfer-encoding must be used. For further details, see 
   [RFC7303].

Security considerations: Package documents contain well-formed XML 
   conforming to the XML 1.0 specification.

   Clearly, it is possible to author malicious files which, for 
   example, contain malformed data. Most XML parsers protect 
   themselves from such attacks by rigorously enforcing conformance.

   All processors that read package documents should rigorously check 
   the size and validity of data retrieved.

   There is no current provision in the EPUB 3 specification for 
   encryption, signing, or authentication within the package document 
   format.

Interoperability considerations: None.

Published specification: This media type registration is for the EPUB 
   package document, as described by the EPUB 3 specification located 
   at https://www.w3.org/TR/epub-33/.

   The EPUB 3 specification supersedes the Open Packaging Format 
   2.0.1 specification, which is located at 
   http://idpf.org/epub/20/spec/OPF_2.0.1_draft.htm and which also 
   uses the application/oepbs-package+xml media type.

Applications which use this media type: This media type is in wide 
   use for the distribution of ebooks in the EPUB format.

Additional information:

   Magic number(s): none

   File extension(s): .opf

   Macintosh File Type Code(s): TEXT

Fragment identifiers: EPUB Canonical Fragment Identifiers are custom 
   fragment identifiers defined for EPUB Publications. They may be 
   used to refer to an arbitrary content within any publication 
   resource defined for the publication. These identifiers are 
   defined at https://idpf.org/epub/linking/cfi/.

Person & email address to contact for further information:
   EPUB 3 Working Group (public-epub-wg&w3.org)

Intended usage: COMMON

Author/Change controller: World Wide Web Consortium (W3C)