Article 15(1) of the Framework Directive requires the adoption of a Recommendation on Relevant Product and Service Markets. The Commission adopted the first edition of this Recommendation on 11 February 2003. The Recommendation identified those product and service markets within the electronic communications sector, the characteristics of which may be such as to justify the imposition of regulatory obligations set out in the specific directives. The markets identified in the Recommendation were defined in accordance with the principles of competition law, without prejudice to markets that may be defined in specific cases under competition law. Article 15(1) of the Framework Directive requires that the Commission regularly reviews the Recommendation. On 25 November 2005, the Commission started the review process by issuing a ‘Call for Input’, which indicated that the Commission would review the Recommendation during the course of 2006. The views gathered in the call for input have provided input to the draft of the revised version of the Recommendation. This Explanatory Memorandum outlines in greater detail the reasoning behind the proposed changes to the Recommendation.