A program-described file can be dictionary-described. You can describe the record format information using interactive data definition utility (IDDU). Even though the file is program-described, AS/400 Query, Client Access, and data file utility (DFU) will use the record format description stored in the data dictionary.
An externally described file can also be dictionary-described. You can use IDDU to describe a file, then create the file using IDDU. The file created is an externally described file. You can also move into the data dictionary the file description stored in an externally described file. The system always ensures that the definitions in the data dictionary and the description stored in the externally described file are identical.