CIF - Dictionary Definition Language (DDL)

Last Update Nov. 27, 995
CIF Editor

Abstract

The Dictionary Definition Language (DDL) is perhaps the most difficult part of CIF to understand. Simply stated it is a description of how to describe a dictionary which is itself a STAR and CIF compliant file.

At present there are two versions of the DDL, one used by the mmCIF dictionary referred to as DDL v2.x and the published version used by the other dictionaries, referred to as v1.x. Efforts have been made to make v2.x backward compatible to DDL v1.x.

Further information is available as follows (again much os this is taken from the IUCR Web site and now the Rutgers site).

Background

DDL 1.x