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Department of Defense Discovery Metadata Specification (DDMS) Home Page

DDMS 5.0 is now available

Welcome to the Department of Defense Discovery Metadata Specification (DDMS) Home Page! Here you will find current information about the DDMS and links to related documentation and resources. If you're looking for DDMS-related projects, you can find them here. If you're looking for the CM process surrounding the DDMS follow the "Configuration Management" link. To contact the DoD MWG or the Metadata Registry team follow "The DoD MWG" and the "Contact Us" links respectively. If you're just looking to get started with the DDMS right away, you can download the most current DDMS release package here.

Each DDMS Release includes all of the relevant information for that version of the DDMS including the DDMS Specification, the XML Schema, Release Notes including the changes from the prior version and developers' notes, sample DDMS instance documents, and other related information deemed useful for understanding that version.

The DDMS is dependent on other schemas provided by the Director of National Intelligence Chief Information Officer, the National Geospatial Intelligence Agency, International standards organizations and commercial standards.

The most recent DDMS schema and documentation are always available from the following shortcut URLs (DSE login required):

Schema: http://purl.org/ddms/current-schema
Specification: http://purl.org/ddms/current-specification
Full package: http://purl.org/ddms/current_package

In addition, specific packages have permanent URLs based on their release numbers.

We're always looking for ways to improve the DDMS Home Page so if there's anything you would like to see, please let us know.

Table of Contents

DDMS Overview

The DoD Discovery Metadata Specification (DDMS) defines discovery metadata elements for resources posted to community and organizational shared spaces.

"Discovery" is the ability to locate data assets through a consistent and flexible search. Visibility, accessibility, and understandability are the high priority goals of the DoD Net-Centric Data Strategy. Of these goals, visibility and discovery are intimately linked. Visibility of a resource is, in a practical sense, useless, if the resource is not easily discoverable. With the express purpose of supporting the visibility goal of the DoD Net-Centric Data Strategy, the DDMS specifies a set of information fields that are to be used to describe any data or service asset, i.e., resource, that is to be made discoverable to the Enterprise, and it serves as a reference for developers, architects, and engineers by laying a foundation for Discovery Services. The DDMS will be employed consistently across the Department's disciplines, domains and data formats. This document describes the DDMS elements and their logical groupings. It does not provide an interchange specification or substantive implementation guidance. The DDMS elements as specified in this document, however, should provide a basis for organizations to begin planning, transitioning, and implementing metadata tagging initiatives that support the Department's goal of increased data visibility and Enterprise Discovery. The current version of the DoD Discovery Metadata Specification and the current XML implementation can be downloaded via the link below. Previous versions of the DDMS and their XML implementations are also available under "Prior Releases".

Current Versions:

DDMS Version Information

DDMS is cited in both the DoD Information Standards Registry (DISR) and the Intelligence Information Standards Registry (ITSR). DDMS use is mandated for use across DoD and the Intelligence Community (IC). There are two active versions of DDMS at the present time. Version 4.1 is mandated for use across the DoD, while version 5.0 is considered "Emerging". IC developers can use DDMS 4.1 or 5.0 based on their requirements.

DDMS 5.0 [Documentation]

Title: Department of Defense Discovery Metadata Specification (version 5.0)
Creator: Office of the Assistant Secretary of Defense, Networks and Information Integration, Information Managment.
Identifier: urn:us:mil:ces:metadata:ddms:5
Date Issued: January 11, 2013
Schema: http://purl.org/ddms/DDMS_5-schema
Specification: http://purl.org/ddms/DDMS_5-specification
Package: Department of Defense Discovery Metadata Specification, Version 5 Specification, XML Schema, Release Notes, and Sample instance documents.
Document Status:Approved
Description: The Department of Defense Discovery Metadata Specification defines discovery metadata elements for resources posted to community and shared spaces.
Date Valid: January 11, 2013

The DDMS v5 schema is intended to be used as an assertion within a document holding to the IC Trusted Data Format (TDF), such as a Trusted Data Object (TDO). As such, it is dependent on the following:

  • IC-TDF version 2
  • Information Security Metadata (ISM) version 10
  • Need to Know (NTK) version 8
  • VIRT version 1

These schemas will initially be available from Intelink-U at: http://purl.org/ic/standards/Data-Specs

When these schemas are available in public release form they will be available at: http://www.dni.gov/index.php/about/organization/chief-information-officer/ic-cio-enterprise-integration-architecture

DDMS 5 also requires the Time-Space-Position Information package, which includes a number of International Standard schemas as well as US Federal schemas:

  • TSPI version 2.0.0

A comprehensive package of TSPI and its component schemas is available from the DSE (DSE login required) at: https://metadata.ces.mil/dse/ns/GSIP/tspi/2.0.0/tspi.zip

DDMS implementers will need to copy all dependent schemas and Schematron rules, including the related CVE files for IC specs, into folders that are peers to the DDMS, W3C-XML, and XLINK folders found in DDMS.zip.

Note on TDF-1: While it may be possible to use DDMS 5 with TDF 1, it is not recommended. As VIRT is a part of the spec baseline with TDF 2, certain difficulties may be encountered when running the IC Schematron rules. The CVE XML files associated with TDF 1 use a slightly different schema from those associated with TDF 2 and VIRT, requiring either two separate schema trees, or alteration of the XML and/or schema files.

DDMS 4.1 [Documentation]

Title: Department of Defense Discovery Metadata Specification (version 4.1)
Creator: Office of the Assistant Secretary of Defense, Networks and Information Integration, Information Managment.
Identifier: urn:us:mil:ces:metadata:ddms:4
Date Issued: June 12, 2012
Schema: http://purl.org/ddms/DDMS_4_1-schema
Specification: http://purl.org/ddms/DDMS_4_1-specification
Package: Department of Defense Discovery Metadata Specification, Version 4.1 Specification, XML Schema, Release Notes, and Sample instance documents.
Document Status:Approved
Description: The Department of Defense Discovery Metadata Specification defines discovery metadata elements for resources posted to community and shared spaces.
Date Valid: June 12, 2012

The DDMS v4.1 schema is dependent on the following Data Encoding Standards (DES):

  • Information Security Metadata (ISM) version 9
  • Need to Know (NTK) version 7
As well as:
  • IC-Commons, which is distributed in the IRM version 7 distribution package.

These specifications are available in For Official Use Only (FOUO) versions at: https://www.intelink.gov/sites/odni/cio/ea/library/default.aspx

Known Users of the DDMS

Federated Search

The Federated Search Specification and developer's guide are available here.

Access will require a PKI registered with DISA, portal registration, and NCES pilot participation.

DCGS Community

The Distributed Common Ground/Surface System (DCGS) community uses DDMS to power their metadata catalog, DCGS Integration Backone (DIB), as the standard for Discovery of intelligence related information. It organizes information in a way that enables the Warfighter to find what they are looking for using a DIB. The DCGS Multi-Service Execution Team (MET) Office (DMO) and the DCGS SIGINT Functional Team have created a presentation and workbook on DDMS for the 2010 DoDIIS Conference, and these materials can be downloaded in the Related Resources section below. Contact information for this group can be found in the presentation slides.

Related Resources

XSLT Transforms

Reference implementations of Extensible Stylesheet Language Transformations (XSLTs) to upgrade DDMS 2 to DDMS 4.1 and from DDMS 4.1 to 5.0 (as TDO) have been posted to the DSE. Please note that they are reference implementations that end users will need to modify and adapt to fit their own needs, and that resultant DDMS records may be lacking data required to be complete and accurate, as later versions of the specification require data not present in earlier versions. Those using the transformations will need to adapt strategies to fill in this data in accordance with their missions.

Links to the reference implementations (DSE login required) are:

DCGS Presentation and Workbook

These materials were created by the DCGS Multi-Service Execution Team Office (DMO) and the DCGS SIGINT Functional Team, and have been posted with their kind permission. All downloads are fully unclassified and for public release.

Intelligence Community Information Security Markings

Additional Links

Prior Releases:


DDMS Change Log

DDMS 5.0 includes the following changes:

  • Inclusion as a TDF assertion. This is a fundamental structure change that affectively decouples DDMS from direct dependency on and forced updates as a result of IC DES version updates. (CR 2012-11)
  • Removal of the ddms:security element. As a direct result of the above, security metadata captured in the TDF-compliant document would be redundant inside of the DDMS discovery assertion. Note that individual elements of the ddms:resource may still (in some cases, must) use security attributes such as ownerProducer and classification. These equate to portion markings, and should be compatible with the markings in the TDF-compliant document. (CR 2012-11)
  • Use of tspi:Polygon, tspi:Point, tspi:Envelope, tspi:Circle, and tspi:Ellipse elements under geospatialCoverage. This change requires the use of the TSPI schema and its dependencies. (CR 2012-07)
  • Inclusion of a Schematron document to validate country codes against an authoritative web service. (CR 2012-07)
  • Inclusion of a new IC spec, VIRT, for virtualCoverage. This is intended to be a schema independent of DDMS that may be imported or used wherever description of a virtual resource is needed. (CR 2012-10)
  • Allowance of multiple ddms:affiliation elements under a ddms:person

DDMS 4.1 includes several minor changes:

  • New optional, repeatable acquiredOn element added to dates, with the ability to be specified as an approximal date, where the date can be specified in terms of approximate start and end dates or in a descriptive way (CR_2011-18).
  • nonStateActor now includes an optional qualifier attribute (CR_2012-01).
  • CombinedDateType allows dates of the format YYYY-MM-DDThh:mmTZ previously specified as allowed in the annotations, but not actually permitted (CR_2012-02).
  • temporalCoverage has been extended to allow a choice between ExtendedCombinedDateType elements start and end and ApproximableDateType elements approximableStart and approximableEnd, where the date can be specified in terms of approximate start and end dates or in a descriptive way (CR_2012-03).
  • Added an optional ntk:Access to metacardInfo, which was included in the specification for DDMS 4.0 and 4.0.1 but not included in the schema (CR_2012-04).
  • Update the supported version of the DES for ISM to version 9 and NTK to version 7 (CR_2012_05).
See the release notes in the submission package for further details.

DDMS 4.0.1 replaces the ddms:POCType attribute with the ISM pocType attribute, to comply with Schematron rules. (CR 2011-17)

DDMS 4.0 includes several major changes:

  • All element and attribute names have been converted to consistently use camel-case, initial lowercase. This affects the root-level resource (formerly Resource) element, as well as, for example: Person, Organization, Service, and Unknown, and others.
  • Wrapper elements GeospatialExtent, Media, Subject, and TimePeriod have been removed.
  • DDMS 4.0 uses a new URN namespace: urn:us:mil:ces:metadata:ddms:4 (CR 2011-14)
  • New mandatory element metacardInfo, pursuant to CR 2011-15. This is intended to provide information about the DDMS record ("metacard") itself, not the resource being described by it.
  • New optional elements:
    • resourceManagement -- child under ddms:resource (CR 2011-15)
    • noticeList -- child under ddms:resource/ddms:security, and ddms:resource/ddms:metacardInfo. (CR 2011-7)
    • productionMetric -- child under ddms:resource/ddms:subjectCoverage (CR 2011-8)
    • recordsManagementInfo -- child under ddms:resource/ddms:resourceManagement and ddms:resource/ddms:metacardInfo (CR 2011-11)
    • revisionRecall -- child under ddms:resource/ddms:resourceManagement and ddms:resource/ddms:metacardInfo (CR 2011-12)
    • taskingInfo -- child under ddms:resource/ddms:resourceManagement (CR 2011-13)
    • nonStateActor -- child under ddms:resource/ddms:subjectCoverage (CR 2011-15)
    • subOrganization -- child under ddms:organization (CR 2011-10)
  • New optional attributes:
    • POCType -- attribute of ContactInfoType (CR 2011-10)
    • acronym -- attribute of OrganizationType (CR 2011-10)
  • Recommendations are made to map IRM Activity, IntelType, ReportingLevel, and ProductLine to ddms:type, using appropriate qualifiers. (CRs 2011-4, 2011-6, 2011-9)