EXTERNAL | The ASSIGN clause contains a data name or literal that specifies the file's name in the external file-storage environment. |
DYNAMIC |
the ASSIGN clause contains an external-file-reference that specifies the file to the external environment for possible further mapping to an external file-storage environment-name. |
Comments:
For any indexed files, or for all files if the program is compiled using the CALLFH directive, filename mapping overrides any syntax definition or use of the ASSIGN directive.