This International Standard establishes the terminology used in the field of gas cylinders. It also gives definitions relating to pressures and gases in Annex A and Annex B respectively. In addition to terms in English and French, two of the three official ISO languages, this International Standard gives the equivalent terms in German; these are published under the responsibility of the member body for Germany (DIN). However, only the terms and definitions given in the official languages can be considered as ISO terms and definitions.