Required if there is more than one record format for the file.
The value specified in the FORMAT phrase contains the name of the record format to use for this I-O operation. The system uses this to specify or select which record format to operate on.
Identifier-2, if specified, must be a an alphanumeric data item of 10 characters or less.
Literal-1, if specified, must be an uppercase character-string of 10 characters or less.
If the FORMAT phrase is not specified on the I-O statement when indexed files are accessed in random access mode, the first format defined is used.