The Royal Navy's postwar Type numbering

The postwar Type system sorted the Royal Navy's varied hulls and conversions by role. Types 11 to 30 are assigned to anti-submarine frigates, while Types 31 to 40 cover general-purpose frigates. Types 41 to 60 cover anti-aircraft frigates and destroyers, and Types 61 to 80 cover aircraft-direction frigates. Types 81 to 99 cover general-purpose combatants such as frigates, destroyers and sloops; battleships and battlecruisers would fit into the 80s and 90s as large general-purpose combatants. Aircraft-direction ships offered the ability to communicate with fighters from a vessel other than a carrier. Earlier wartime experience and proposed destroyer conversions help explain why that role received its own category.