derogable clauses that entr ench equality within marriage and specify a constitutional minimum age of 18 years for marriage are contemplated. Limitations, exceptions and derogations from these clauses, whether based on tradition, religion or any other ground, should not be permissible. B. Institutional Measures [25] Full and effective compliance with the prohibition against child marriage requires that States Parties undertake institutional measures to ensure implementation of laws and policies alongside robust due diligence and accountability mechanisms to prevent child marriage. The following institutional measures are recommended as mechanisms which will help States Parties to identify and prevent child marriages, protect children from the risk of child marriage and reduce the impacts of child marriage, including for those already married. Implement verification procedures: birth registration, age verification and marriage registration [26] Birth registration is an essential component of the effort to end child marriage, as birth certificates produced on marriage are the most effective means to ensure that children under the age of 18 do not enter into marriage. Birth registration should be compulsory, accessible and free. Marriage officers should be responsible for verifying that both parties to a marriage meet the minimum age requirement of 18 years of age and birth certificates should constitute the preferred means for verification. In the absence of official documentation, marriage officers may rely on objective evidence, such as school or hospital records, to substantiate a child’s 15