EN 50221 : common interface specification for conditional access and other digital video broadcasting decoder applications / European Commitee for Electrothecnical Standardization
EN 50083 -6 : December 1997: cable networks for television signals, sound signals and interactive services: part 6: optical equipment / European Commitee for Electrothecnical Standardization
EN 50248 : December 1997: characteristics of DAB receivers / European Commitee for Electrothecnical Standardization