I have to admit, I am like most people who work in front a computer, guilty of not ever really reading the manual. Today however, I was reading through the “Resource Control Display Configuration XML Reference Guide” and found that on the “create” RCDC for uocTextBox controls, there is an option called: “UniquenessValidationXPath”. This filter allows you to define a check the value for uniqueness within the scope of the filter.
Neat! I need to read more manuals.. no, wait, I didn’t say that..
Edited to add the link for the RCDC Reference Guide: http://technet.microsoft.com/en-us/library/ee534918(WS.10).aspx