Dictionary definition language DDLm

The methods dictionary definition language (DDLm) records CIF data names and their definitions and properties within CIF dictionaries, with descriptions of algorithmic methods for evaluation and validation.

While providing important new functionality to dictionary and applications software developers, DDLm fully supports the definition capabilities of the existing dictionary languages, DDL1 and DDL2, but provides a higher level of semantic content for domain dictionaries. Note that no changes are required in existing archival data files written with reference to DDL1 or DDL2 dictionaries in order to apply domain dictionaries written in DDLm.

The document linked below defines the meanings of the DDLm attributes themselves, in a plain text DDLm dictionary. A brief introduction to reading DDLm dictionaries is also available.

Current version

• Version 4.1.0 of 13 January 2023
• HTML version
• Formatted pdf version

Archival versions

• Version 3.14.0 of 25 September 2019
• Version 3.11.09 of 7 May 2015

Background material

An earlier draft from August 2008 gives a good overview of the way in which new features of DDLm work. Note that some details will differ from the version finally accepted.

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Updated 14 August 2020