(14)Binding technical standards contribute to a single rulebook for financial services legislation as endorsed by the European Council in its conclusions of June 2009. To the extent that certain requirements in Union legislative acts are not fully harmonised, and in accordance with the precautionary principle on supervision, binding technical standards developing, specifying or determining the conditions of application for those requirements should not prevent Member States from requiring additional information or imposing more stringent requirements. Technical standards should therefore allow Member States to do so in specific areas, when those legislative acts provide for such discretion.