The division headquarters itself has also been redesigned as a modular unit that can be assigned an array of units and serve in many different operational environments. The new term for this headquarters is the UEx (or Unit of Employment, X). The headquarters is designed to be able to operate as part of a joint force, command joint forces with augmentation, and command at the operational level of warfare (not just the tactical level). It will include organic security personnel and signal capability plus liaison elements. As of March 2015, nine of the ten regular Army division headquarters, and two national guard division headquarters are committed in support of Combatant Commands.