Junior Commissioned Officer (JCO) is a term used for a group of military ranks which is higher than havildar (non commissioned officer) and lower than lieutenant (commissioned officer). The term is only used by Bangladesh, India, and Pakistan. Senior havildars are promoted to JCO rank on the basis of merit and seniority, restricted by the number of vacancies. JCOs are treated as a separate class and hold additional privileges. Primarily the term was associated with armies but since the 2000s India and Pakistan's navies and air forces are using the term to indicate their Chief Petty Officers and Warrant Officers.