(31)Regulation (EC) No 223/2009 provides for a reference framework for European statistics and requires Member States to comply with the statistical principles and quality criteria specified in that Regulation. Quality reports are essential for assessing, improving and communicating the quality of European statistics. The ESSC has endorsed the single integrated metadata structure as the ESS standard for quality reporting, thereby helping to satisfy, through uniform standards and harmonised methods, the statistical quality requirements laid down in Article 12(3) of that Regulation. That ESS standard is to contribute to the harmonisation of quality assurance and reporting under this Regulation.