The British took the lead in developing the armored vehicle now known as the tank. On 24 December 1915, a meeting took place of the British Inter-Departmental Conference to discuss the progress of the plans for what were described as "Caterpillar Machine Gun Destroyers or Land Cruisers." It was agreed that "it was very desirable to retain secrecy by all means, and proposed to refer to the vessel as a "Water Carrier." In Government offices, committees and departments were always known by their initials. But the proposed title was considered totally unsuitable (in British English "WC" = toilet) In the search for a synonymous term, they changed the word "Water Carrier" to "Tank."

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