In my xsd I'm using negate to check for disallowed characters. This is within a restriction pattern tag:
^[^ab]+$
This will allow any string unless it contains either a or b.
My requirement is that the string can contain anything but a or b or cd (where c is allowed and d is allowed and dc is allowed but not cd).
From what I've read the Metacharacters inside square brackets does not include ( ) 's for grouping.
Is there another way to meet my requirement so that the xsd will validate that we are receiving valid data?
Thank You very much for your assistance.
