The Department of Defense Discovery Metadata Specification (DoD Discovery Metadata Specification or DDMS) is a Net-Centric Enterprise Services

Net-Centric Enterprise Services

Net-Centric Enterprise Services is a Department of Defense program, managed by the Defense Information Systems Agency, to develop information technology infrastructure services for future systems used by the United States military....

 (NCES) metadata

Metadata

The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...

 initiative

Initiative

In political science, an initiative is a means by which a petition signed by a certain minimum number of registered voters can force a public vote...

. DDMS is loosely based on the Dublin Core

Dublin Core

The Dublin Core metadata terms are a set of vocabulary terms which can be used to describe resources for the purposes of discovery. The terms can be used to describe a full range of web resources: video, images, web pages etc and physical resources such as books and objects like artworks...

 vocabulary. DDMS defines discovery metadata element

Data element

In metadata, the term data element is an atomic unit of data that has precise meaning or precise semantics. A data element has:# An identification such as a data element name# A clear data element definition# One or more representation terms...

s for resources

Resource (computer science)

A resource, or system resource, is any physical or virtual component of limited availability within a computer system. Every device connected to a computer system is a resource. Every internal system component is a resource...

 posted to community

Community

The term community has two distinct meanings:*a group of interacting people, possibly living in close proximity, and often refers to a group that shares some common values, and is attributed with social cohesion within a shared geographical location, generally in social units larger than a household...

 and organization

Organization

An organization is a social group which distributes tasks for a collective goal. The word itself is derived from the Greek word organon, itself derived from the better-known word ergon - as we know `organ` - and it means a compartment for a particular job.There are a variety of legal types of...

al shared spaces

Spaces

Spaces may refer to:* Windows Live Spaces, the next generation of MSN Spaces.* Spaces , a virtual desktop manager implemented in Mac OS X Leopard* Gaps, a solitaire card game*Spaces, a 1974 album by Larry Coryell...

. It is sometimes (incorrectly) referred to as DoD Discovery Metadata Standard. The project focuses both on the process of developing a central taxonomy for metadata, and defining a way of discovering resources by their metadata using that taxonomy.

The DDMS was created in support of the DoD Net-Centric Data Strategy (dated May 9, 2003), and specifies a set of information fields that are to be used to describe any data or service asset that is made known to the DoD Enterprise. The elements in the DDMS are designed to be platform, language, and implementation-independent, and the specification is described with an XML Schema

XML Schema

XML Schema, published as a W3C recommendation in May 2001, is one of several XML schema languages. It was the first separate schema language for XML to achieve Recommendation status by the W3C...

.

Structure

The DDMS is designed using a layered approach, combining a Core Layer and an Extensible Layer surrounded by the DDMS Resource Header. The Core Layer is composed of five sets of element categories, each with a specific functional focus for describing a data asset:

• The Metacard elements describe the DDMS resource itself.
• The Security elements enable the description of security classification of the described resource, Need-to-Know (NTK) information, and related notices.
• The Resource elements enable the description of maintenance and administration information.
• The Summary Content elements enable the description of concepts and topics.
• The Format elements enable the description of physical attributes of the asset.
• The Extensible Layer is designed to support domain-specific or Community of Interest
  Community of interest
  A community of interest is a community of people who share a common interest or passion. These people exchange ideas and thoughts about the given passion, but may know little about each other outside of this area...
  
   (COI) discovery metadata
  Metadata
  The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
  
  requirements, and can be used to extend the element categories identified in the Core Layer. Extensions are expected to be registered in the DoD Metadata Registry. Extensible attribute spaces are also provided on some elements.

Versioning

The DDMS is currently on version 4.0.1 released on November 18, 2011. This release corrects the implementation of the IRM POC type attribute. The current supported Information Security Marking (ISM) version is V7.

Earlier versions include:

• DDMS Version 4.0 (released September 22, 2011)
• DDMS Version 3.1 (released July 5, 2011)
• DDMS Version 3.0.1 (released March 4, 2011, documentation update only)
• DDMS Version 3.0 (released September 2, 2010)
• DDMS Version 3.0 Pre-Release (released January 2010, pending ICISM modification).
• DDMS Version 2.0 (released July 17, 2008)
• DDMS Version 1.4 (released July 1, 2007)
• DDMS Version 1.3 (released July 29, 2005)
• DDMS Version 1.2 (released January 3, 2005)
• DDMS Version 1.1 (released July 1, 2004)
• DDMS Version 1.0 (released September 29, 2003)

Major version releases contain changes which break backwards compatibility with earlier versions.