We have an increasing need to geographically segment constituents for site-specific CRM tasks such as querying, reporting and correspondence processes. Our constituents can have multiple sites so we need a way to indicate a primary site that can be used in these tasks. It would be based on the ZIP of the primary address and there would be two global processes: one to add or flag the primary site for new constituents and one to change the primary site if some change is made to the primary address or to the underlying zip code-to-site table.