"This Technical Report gives explanation on the pressure definitions used by the gas network operators with regard to the standards of CEN/TC 234 ""Gas Infrastructure"". The European Standards of CEN/TC 234 comprise the functional requirements in the field of gas infrastructure from the input of gas into the on-shore transmission network up to the inlet connection of gas appliances@ including transmission@ distribution@ storage@ compression@ pressure regulation and metering@ installation@ injection of non-conventional gases@ gas quality issues and others."