The FILE XFD directive supplies a starting name from which the XFD file name is formed. This XFD directive is required only when the file name in the COBOL code is nonspecific. For example, use this XFD directive when the SELECT for the file has a variable ASSIGN name (ASSIGN TO variable_name). In this case, the Connector cannot form a file name automatically, and you must provide a name. The starting name serves as the basis for the XFD name.
This XFD directive must appear on the line immediately preceding the file's FD.
Suppose your SELECT statement has a variable ASSIGN name such as the one shown here:
select my-file assign to my-variable.
Then you would need to add the FILE XFD directive as shown here:
select my-file assign to my-variable. . . . $xfd file=payroll fd my-file