
In Commonwealth countries, warrant officers have usually been included alongside NCOs and enlisted personnel in a category called other ranks (ORs), which is equivalent to the US "E" category (i.e. US WOs are usually experts in a particular technical field, with long service as enlisted personnel in some cases, however, direct entrants may become WOs-for example, individuals completing helicopter pilot training in the US Army Aviation Branch become flight warrant officers immediately. However, chief warrant officers are officially commissioned, on the same basis as commissioned officers, and take the same oath. Warrant officers in the United States are classified in rank category "W", which is distinct from "O" (commissioned officers) and "E" ( enlisted personnel). Nevertheless, WOs in the British services have traditionally been considered and treated as distinct from non-commissioned officers. It was first used during the 13th century, in the Royal Navy, where warrant officers achieved the designation by virtue of their accrued experience or seniority, and technically held the rank by a warrant, rather than by a formal commission (as in the case of a commissioned officer). The name of the rank originated in medieval England. Warrant officer ranks are especially prominent in the militaries of Commonwealth nations and the United States. Depending on the country, service, or historical context, warrant officers are sometimes classified as the most junior of the commissioned officer ranks, the most senior of the non-commissioned officer (NCO) ranks, or in a separate category of their own.

Warrant officer ( WO) is a rank or category of ranks in the armed forces of many countries. The Regimental Sergeant Major of the Royal Bermuda Regiment, WO1 Herman Eve, in 1992 Comparative military ranks
