In order to support correlation between two different systems; i.e. CRM and VersionOne, it would be nice to be able to prevent accidential duplication of data entry and to be able to query on a Reference Number for the external system.

I must be able to correlate some of the WorkItems with an external CRM system. I have a custome filed added to User Stories and Defects to store the Reference Number to the CRM system record. However, I am able to accidentially crate duplicates of the same Reference Number and am unable to search for the Reference number.