Oracle Message ORA-08469 - must use the SIGN IS SEPARATE clause in mask options

ERRORmust use the SIGN IS SEPARATE clause in mask options
CAUSEA signed numeric entry with DISPLAY usage was converted using a non-defaulted character set and its PICTURE character-string contains an S. In these circumstances, a SIGN IS SEPARATE clause must be specified in the mask options.
ACTIONEither specify a valid SIGN IS SEPARATE clause in the mask options, use the defaulted character set, or dont specify an S in the PICTURE character-string.