Coding Standards for Database Files › Data Dictionary/Field Reference File › Standard for Field Reference Files › Structuring the Field Reference File › Secondary Reference Fields

Secondary Reference Fields

The secondary field section should contain definitions of all fields in the system database files.

When the field is of a standard type, for example, already defined as a primary field, the field should be defined by reference to its primary field—that is to say using REFFLD(*SRC). In such cases, only the column headings need to be redefined.

Fields should only be defined with reference to a type field when there is a genuine dependence. A simple test of this is to ask the question: If I were to change the definition of the based-on field, would I want the definition of the dependent field to change as well?

When appropriate (for example, for total fields) use relative lengths (+-)n to increase or decrease field lengths with respect to the based-on field.

Each field should be fully defined with edit codes/words, text, ranges, values, display attributes, etc. Use the DDS COLHDG keyword rather than the TEXT keyword as it provides neater documentation.

Note: It is important that definitions are as full as possible, as they constitute the central reference information for the whole database.

The format identifier for all secondary reference fields should be ‘$$’. (This may be controlled in CA 2E generated databases by the YFRFPFX model value.)

Fields should be in alphabetical order within the section. They should be indexed by mnemonic. This provides a self-updating list of the mnemonics that have been used.