Section 3.1.6.1. Dictionary identification

Dictionary files must contain information that unambiguously states their identity and version. In DDL2-based dictionaries this is done using the dictionary attributes described in Section 2.6.6.4 . The name of the data block comprising the whole content of a DDL2 dictionary is by convention the same as the dictionary identification string given as _dictionary.title. This value is repeated as the value of _dictionary.datablock_id (see Example 3.1.6.1) for use in checking the consistency of the dictionary.

The dictionary history is also an important audit record of changes to the dictionary content. Unlike in DDL1-based dictionaries where the history is contained in a single field, DDL2 provides a looped list of version labels, dates and annotations. For convenience, the history records in large DDL2-based dictionaries are sometimes placed at the end of the dictionary file.