Standardization of terminology, quality specifications, methods of measurement, sampling, analysis and test for natural gas and natural gas substitutes (gaseous fuel, including biogas, biomethane, coalbed methane, shale gas and wet gas) in all its facets from production to delivery to all possible end users across national boundaries, and standardisation of specifications for natural gas and biomethane as fuel for engines and of biomethane for injection in the natural gas grid, including any necessary related methods of analysis and testing. Also, standardization in the field of analysis of gases, including terminology, preparation of gas mixtures, sampling, transfer lines, analytical methods, including evaluation of characteristics of the analysers.