A Warrant Officer is an officer who had been promoted by working his way up from the ranks, thereby gaining authority to be selected to be given a Warrant by his Commander-in-Chief, as distinguished from a Commissioned Officer who is designated an officer by a commission.
Sub-Conductors or Conductors, who were Warrant Officers, were in existence in India in 1821, (see below) but the introduction date is unclear
The 1921 India Office List contains a list of “Non-Departmental Warrant Officers”.The men in this list mostly have the title Sergeant-Major or Quarter Master Sergeant (Q M S) They were of Warrant Officer 2 rank, and ranked lower than Conductors and Sub-Conductors.
- Warrant Officer Wikipedia
- "Misconduct of a Conductor & a Sub Conductor punished" The Calcutta Annual Register 1821 Chapter III, Public Documents, page 60 [of this chapter]
- 1921 Indian Army List page 1879-80 (digital file page 1223)