A broad arrow, of which a pheon is a variant, is a stylised representation of a metal arrowhead, comprising a tang and two barbs meeting at a point. It is a symbol used traditionally in heraldry, most notably in England, and later by the British government to mark government property. It became particularly associated with the Board of Ordnance, and later the War Department and the Ministry of Defence. It was exported to other parts of the British Empire, where it was used in similar official contexts.

The Board of Ordnance was a British government body. Established in the Tudor period, it had its headquarters in the Tower of London. Its primary responsibilities were 'to act as custodian of the lands, depots and forts required for the defence of the realm and its overseas possessions, and as the supplier of munitions and equipment to both the Army and the Navy'. The Board also maintained and directed the Artillery and Engineer corps, which it founded in the 18th century. By the 19th century, the Board of Ordnance was second in size only to HM Treasury among government departments. The Board lasted until 1855, at which point it was disbanded.