1. The Commission shall draw up and publish in the Official Journal of the European Union a list of non-compulsory standards or specifications to serve as a basis for encouraging the harmonised provision of electronic communications networks, electronic communications services and associated facilities and associated services. Where necessary, the Commission may, following consultation of the Committee established by Directive (EU) 2015/1535, request that standards be drawn up by the European standardisation organisations (European Committee for Standardisation (CEN), European Committee for Electrotechnical Standardisation (Cenelec), and European Telecommunications Standards Institute (ETSI)).

2. Member States shall encourage the use of the standards or specifications referred to in paragraph 1 for the provision of services, technical interfaces or network functions, to the extent strictly necessary to ensure interoperability of services, end-to-end connectivity, facilitation of provider switching and portability of numbers and identifiers, and to improve freedom of choice for users.

In the absence of publication of standards or specifications in accordance with paragraph 1, Member States shall encourage the implementation of standards or specifications adopted by the European standardisation organisations.