Regimental sergeant major (RSM) is an appointment that may be held by a warrant officer (WO) in the British Army, the Royal Marines, and the armies of many other Commonwealth and former Commonwealth nations. It is also an actual rank in the Irish Defence Forces, and formerly in the British Army, Royal Marines and United States Army. Only one warrant officer holds the appointment of RSM in any regiment or battalion, making them the senior warrant officer; in a unit with more than one top-ranked WO, the RSM is considered to be first amongst equals".[citation needed] The RSM is primarily responsible for assisting their commander in maintaining standards and discipline amongst the non-commissioned members and acts as a parental figure to their subordinates, sometimes referred to by the mantra "Drill, Dress and Discipline".[citation needed]