When constructing a picture validation function, you should refer to the picture control characters by their position in the _dpictbl[ ] array. This will allow the symbols chosen as control characters to be changed.
For example, as the system is supplied _dpictbl[2].dp_sym is the character '9', which is associated with the numeric picture control function. The character '9' can be changed to another value, but dpictbl[2].dp_sym will always contain the character associated with the numeric picture control function.
For convenience in referring to the picture control character in picture validation functions, you may wish to use the #defined values for the picture control characters. These values are defined in vv_form.h. The #define assigns a name to the number of the position that the control function has in the array. For example, DIGIT is #defined as 2; thus the numeric picture control character is referenced by _dpictbl[DIGIT].dp_sym.
