Note: The DoD Metadata Registry has been replaced by the DoD Data Services Environment (DSE).
The Department of Defense (DoD) Data Services Environment (DSE) is managed by the Defense Information Systems Agency (DISA). The DSE provides a single location to DoD data source directories to improve search, access, consistency, and integration of data services as well as to increase collaboration among data producers and consumers. Its goal is to simplify the publication and discovery of data services that facilitate information sharing across the Department of Defense.
The DSE enables developers to reuse, understand, and share existing data assets. It addresses structural and semantic metadata such as schemas, web service description language, stylesheets, and taxonomies; descriptive metadata about proposed and approved ADSs, including their relationships and their responsible governance authorities; and descriptive, semantic, and structural metadata about services and other functional capabilities, including service definitions and specifications that can be discovered for subsequent use. The DSE has a Web-based interface with streamlined metadata registration and discovery capabilities that support the visibility of DoD operational capabilities, data standards, and data needs. The DSE provides a number of service interfaces supporting both design-time and run-time access to metadata, and it interacts with other registries and repositories through Open Search federation. 
DOD Instruction 8320.02 directs heads of DOD components to register authoritative data sources and metadata in DOD’s DSE.
AcqLinks and References:
-  Website: DoD Instructions
- Website: https://metadata.ces.mil (Broken)