(4)The Single Integrated Metadata Structure (SIMS)note was approved as a metadata standard by the European Statistical System Committee. The Commission invited Member States to ensure that their national statistical authorities apply the statistical concepts listed therein when compiling reference metadata and quality reports and when exchanging reference metadata and quality reportsnote. The application of SIMS contributes to the harmonisation of quality assurance and reporting, thereby helping to meet the statistical quality requirements of Regulation (EC) No 223/2009 of the European Parliament and of the Councilnote, which provides a mandatory reference framework for European statistics.