permit when he sought an extension. His attempts to demonstrate that he was still living with the person at the relevant time (including a letter from the person herself) were rejected, as the records were essentially regarded as conclusive conclusive. The substantive issue before the court was whether the permit could be withdrawn retroactively, but the Advocate-General noted that the evidential issue fell to be assessed under the principles of equivalence and effectiveness, noting as follows [these are the standard statements]: ‘it is for the domestic legal system of each Member State to lay down the detailed procedural rules governing actions for safeguarding [rights derived from EU law]. The Member States, however, are responsible for ensuring that those rights are effectively protected in each case. The detailed procedural rules governing those actions (…) must not render practically impossible or excessively difficult the exercise of rights conferred by EU law’. It was left to the national court to determine whether or not the rules it applied made it practically impossible for Mr Unal to prove he had lived where he said he did. The above is an example of how the effectiveness principle may be brought into play by rules which make it impossible for a person to adduce the evidence needed to invoke their EU law rights. It is a case-by-case question of fact whether the national rule has this effect or not, but it seems clear that a similar approach could be applied here. If it is effectively impossible – because no evidence, however credible, can rebut the police protocol – the person may be deprived of an opportunity to challenge the waiver. An argument can be made to that effect:  Argue: A rule of national law which, in effect, renders the police protocol / minutes conclusive and prevents the leading of any evidence to the contrary should be regarded as incompatible with the principle of effectiveness if they render practically impossible the exercise of the right envisaged by Article 3 of the Directive. Such a rule has to be interpreted in such a way as to enable the person validly to dispute the waiver. If it cannot be so interpreted, it should be set aside. 28