Differing from regulations, directives and decisions, recommendations (as well as opinions) are not binding for Member States.
According to the terms of the Treaty (TEC) «In order to ensure the proper functioning and development of the common market, the Commission (…)formulate recommendations or deliver opinions on matters dealt with in this Treaty, if it expressly so provides or if the Commission considers it necessary».
Concretely recommendation can be used by the Commission in order to avoid a distortion of competition due to the establishment or the modification of internal norms of a Member State. If this country does not conform itself to this recommendation, the Commission cannot propose to the Council the adoption of a Directive directed to other Member Countries, in order to elide this distortion. The Recommendation is an instrument of indirect action aiming at the approach of legislation of Member States, differing from the Directive only by the absence of obligatory power.