First published as AS (E)CK501-1945 and AS (E)K515-1945.AS CK4-1947 first published as part of AS (E)CK501-1945.AS (E)K515-1945 and part of AS (E)CK501-1945 revised, amalgamated and redesiganted as AS K98-1947.Second edition AS CK4-1962.Second edition AS K98-1962.AS CB1 Int 4 first published 1965.AS CB1 Int 7 first published 1975.AS CK4-1962, AS K98-1962, AS CB1 Int 4-1965 and AS CB1 Int 7-1975 revised, amalgamated and redesignated as AS 2453-1981.Second edition 2004.Reconfirmed 2017. Originated as AS (E)CK501-1945 and AS (E)K515-1945. Previous edition AS 2453-1981. Second edition 2004.