Machinery Safety, Article 5 of 98/37/EC:

(2) Where a national standard transposing a harmonized standard, the reference for which has been published in the Official Journal of the European Communities, covers one or more of the essential safety requirements, machinery or safety components constructed in accordance with this standard shall be presumed to comply with the relevant essential requirements.

Member States shall publish the references of national standards transposing harmonized standards.

Electromagnetic Compatibility (EMC), Article 7 of 89/336/EEC

1. Member States shall presume compliance with the protection requirements referred to in Article 4 in the case of apparatus which is in conformity;

(a) with the relevant national standards transposing the harmonized standards, the reference numbers of which have been published in the Official Journal of the European Communities. Member States shall publish the reference numbers of such national standards;