(13)In order to achieve the Community's objectives through the removal of internal market barriers, it is necessary to replace Member States' existing, divergent general clauses and legal principles. The single, common general prohibition established by this Directive therefore covers unfair commercial practices distorting consumers' economic behaviour. In order to support consumer confidence the general prohibition should apply equally to unfair commercial practices which occur outside any contractual relationship between a trader and a consumer or following the conclusion of a contract and during its execution. The general prohibition is elaborated by rules on the two types of commercial practices which are by far the most common, namely misleading commercial practices and aggressive commercial practices.