There are several elements of COBOL FDs that require special handling when XFDs are built. These include multiple record definitions, REDEFINES, FILLER, and OCCURS. This help section describes how the compiler handles each of these situations.
As described earlier, in many instances you can override the default behavior described below by placing directives in the FDs of your COBOL code. For example, the WHEN directive enables you to use multiple definitions for a single set of data by specifying when each definition should be used. Directives are described in Using XFD Directives.
Like most data sources, AcuXDBC does not support the notion of multiple definitions for the same column. Whenever a COBOL program gives more than one definition for the same data, the compiler makes a choice about which definition to use in the XFD. Then it disregards the rest.