Stairway, Enclosed : A stairway in a building, physically separated (e. g. by walls, partitions, screens, etc. from the accommodation through which it passes, but not necessarily a protected stairway. (BS 4422(3))
H. J. Porter (Chairman - Technical Committee), Dictionary of Fire Technology, The Institution of Fire Engineers, The Victory Press (Leicester) Ltd. 1979 UK. (Fr Tech - Brit) {81}