(21)Persons or organisations regarded under national law as having a legitimate interest in the matter must have legal remedies for initiating proceedings against unfair commercial practices, either before a court or before an administrative authority which is competent to decide upon complaints or to initiate appropriate legal proceedings. While it is for national law to determine the burden of proof, it is appropriate to enable courts and administrative authorities to require traders to produce evidence as to the accuracy of factual claims they have made.