ČSN EN 16723-2

This European Standard specifies the requirements and test methods for natural gas (group L and H, as in EN 437), biomethane and blends of both at the point of use as automotive fuels.
This European Standard applies to the previously mentioned fuels irrespective of the storage state (compressed or liquefied).
To check compliance with some requirements set by the standard, LNG or liquefied biomethane should be re-gasified prior to testing.