The Command and Control Registry (C2R) is the Address Book used by the Army. It dynamically coordinates and collaborates command and control naming, addressing, network and operations data across many different types of military systems deployed globally. It is utilized by Army' systems as the on-line repository for addressing information such as email addresses, military addresses and network information. It is the key ingredient that makes military messaging work seamlessly for our soldiers. The C2R provides a robust suite of interfaces for easy integration into any application and is relied upon by many war-fighter applications to provide critical data for their mission. C2R is widely fielded to Army and Marine units.