Sign representation affects the processing and interaction of zoned decimal and internal decimal data.
Given X'sd', where s is the sign representation and d represents the digit, the valid sign representations for zoned decimal (USAGE DISPLAY) data without the SIGN IS SEPARATE clause are:
The COBOL NUMPROC compiler option affects sign processing for zoned decimal and internal decimal data. NUMPROC has no effect on binary data, national decimal data, or floating-point data.
Based on this assumption, the compiler uses whatever sign it is given to process data. The preferred sign is generated only where necessary (for example, when unsigned data is moved to signed data). Using the NUMPROC(PFD) option can save processing time, but you must use preferred signs with your data for correct processing.
If an unsigned, zoned-decimal sender is moved to an alphanumeric receiver, the sign is unchanged (even with NUMPROC(NOPFD) in effect).