A. Warrant officer one (WO1) / chief warrant officer two (CW2): A WO1 is an officer appointed by warrant with the requisite authority pursuant to assignment level and position given by the Secretary of the Army. CW2s and above are commissioned officers with the requisite authority pursuant to assignment level and position as given by the President of the United States. WO1's and CW2's primary focus is becoming proficient and working on those systems linked directly to their AOC/MOS, that is, their area of concentration (officer AOC), or an enlisted rank's military occupational specialty (MOS). Warrant officers are classified by warrant officer military occupational specialty, or WOMOS. As they become experts on the systems they operate and maintain, their focus migrates to integrating their systems with other branch systems.