Standard Master File Attributes for a Sequential Data Source

Most standard Master File attributes are used with sequential data sources in the standard way. For more information, see Identifying a Data Source, Describing a Group of Fields, and Describing an Individual Field.

Note that file and segment declarations are optional for simple sequential data sources that you are not joining. However, they are recommended in order to make the data source description self-documenting, and to give you the option of joining the data source in the future.