 The NCC created 12 Welsh Areas of Search; they mostly follow county borders, but the larger counties (Dyfed, Powys and Gwynedd) were divided into multiple Areas using district borders.Mid and South Glamorgan were merged into a single AOS, whilst Llanelli district was included in the West Glamorgan AOS.Due to subsequent local government reorganisation in the UK since 1972, many counties and districts have been divided, merged or renamed.