A United States data item description (DID) is a completed document defining the data deliverables required of a United States Department of Defense contractor. A DID specifically defines the data content, format, and intended use of the data with a primary objective of achieving standardization objectives by the U.S. Department of Defense. The content and format requirements for DIDs are defined within MIL-STD-963, Data Item Descriptions (1997).
The terminology of DIDs and the term contract data requirements list (CDRL) originated with US military procurements, and it is now often encountered in other large procurements that are modeled after the military procurement process. Within a military solicitation or contract, each DID is uniquely numbered to identify the data deliverables in terms of specific information such as: purpose, description, preparation instructions including a table of contents and descriptions of each section, and references to the Contract Statement of work (SOW).
Practices and terms where definition is given by MIL-STD-963:
Tailoring: Deletion of a portion of the description of what the deliverable is to contain. DIDs shall be structured to facilitate the tailoring (deletion) of requirement for sections of the content. Each DID paragraph containing format and content descriptions shall be identified by letter or number so that a specific contract may reference a DID and indicate sections of it that are not required in the CDRL. Requirements maybe tailored out, but additional requirements shall not be added by tailoring. A deliverable should leave that section number and title with no content in it to avoid additional costs of producing a custom template and difficulties in review or reference use of the data item which would result if section numbers and titles varied from contract to contract.
Format: Data format, such as that required to meet interface requirements (e.g., data will be put into a specific database system). Whenever possible, contractor format is allowed by the DID. For a specific contract, any restriction of this to a particular file or other format will be provided by the CDRL specification.
Content: The content section of each DID describes the requirements of subject(s), topic(s), or element(s) for the data item. This may be a string of defined data elements for entry into a Government database (e.g., DI-MGMT-81861 Integrated Program Management Report shows the terms and meanings for parts of the XML format file), or a listing of paragraph titles or topics for inclusion (e.g., DI-IPSC-80690 System/Subsystem Specification). For a specific contract, the content of a deliverable shall contain information that fulfills the requirements identified in the CDRL and the description of the DID. Documents should have section numbers and titles matching to the subsections of the DID content description for easier application and use.
DID number: Each DID is assigned a unique three-part identifier by the DID approval authority. An example DID number for repetitive use is DI-CMAN-80013B (DI- Data Item; CMAN – four character code for Standardization Area (see "SD-1, Standardization Directory" for descriptions); 80013 assigned number where the first digit indicates DOD-wide or limited to a specific agency, and B the sequential version). An example DID number for one-time use is OT-1997-12068 (OT- One Time; 1997 – fiscal year issued; 12068 – number assigned from the proponent's block of numbers.
Since DID documents are what contract mechanics cause to be produced, the defined content guidelines and their terminologies are commonly referred to in United States Military Standards or other forms of procedural and administrative guidance of the United States Department of Defense.
Writers of a SOW often include requirements that belong in other parts of a contract. Specifically, quantitative technical requirements are addressed in the military specification and work requirements are specified in the SOW, and data requirements (e.g., delivery, format, and content) should be in the CDRL along with the appropriate DID to minimize the potential for conflict.
