Purpose and key features

containerMD is an XML Schema that defines technical metadata for container digital files. It is mainly intended to be used as an extension schema within METS or PREMIS descriptions of the same file, but it can also be used as a standalone file, for instance as an output format for a characterization tool. It is maintained by the Bibliothèque nationale de France in collaboration with Harvard Library.

containerMD provides the following key features:

• A description of the container file itself in a ‹container› element.
• Optionally, a description of the contained filestreams (see the PREMIS data dictionary version 3, p. 279, for a description of filestreams) - called "entries" in the following text - through an ‹entry› element. Two options are provided:
• 1. Describing each entry in a ‹entry› element ("verbose mode") by recording fixity, format and encoding information, and/or wrapping format-specific metadata in a ‹mdSec› element,
  2. Describing entries grouped by format ("non verbose mode") by recording in an ‹entriesInformation› element the number of entries of a certain format, their minimum and maximum size, their earliest and latest dates, etc.
• Extensions, at the container and/or entry/entries levels, that express fields specific to certain container formats. As of now, the implemented extensions are for supporting:
• 1. the ARC file format (in its version 1.0), a web archive specific container file format aggregating each file harvested on the Web in a dedicated ARC record,
  2. its successor, the WARC file format (from its version 1.1),
  3. disk images file formats (in its version 1.2).

Further on, other extensions for container formats like ZIP may be added.

• Ability to include format-specific technical information for a contained file. For this purpose the PREMIS ‹mdSec› element was reused.

Comments on the schema can be sent to the .

Schema and documentation

• schema: http://bibnum.bnf.fr/schema/containerMD-v1_2.xsd
• documentation: http://bibnum.bnf.fr/containerMD-v1_2/documentation. Note: start with the "containerMD" root element to browse the schema more easily

Implementation guidelines and examples

Previous version

Dated: 2014, september 25th

Last updated: 2020, september 3rd