Department of Defense Discovery Metadata Specification
The Department of Defense Discovery Metadata Specification is a Net-Centric Enterprise Servicesmetadatainitiative. DDMS is loosely based on the Dublin Core vocabulary. DDMS defines discovery metadata elements for resources posted to community and organizational shared spaces. It is sometimes 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, 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.
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 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 discovery metadata requirements, and can be used to extend the element categories identified in the Core Layer. Extensions are expected to be registered in the . Extensible attribute spaces are also provided on some elements.
Versioning
The DDMS is currently on version 5.0 released on January 14, 2013. This is the first version to recast DDMS within the bounds of the Intelligence Community's Trusted Data Format specification. In this paradigm, the DDMS metacard is not a standalone top-level construct. Instead, it is a single assertion which decorates a Trusted Data Object, and which is incomplete on its own. DDMS 5.0 also replaces the Geography Markup Language profile for geospatial information with Time-Space Position Information v2.0. DDMS 5.0 requires TDF V2 and associated IC specifications. Earlier versions include:
