(2017) 1 African Human Rights Yearbook 133 during the 28th AU Summit in Addis Ababa in June/July 2017, the Executive Council emphasised the ‘right of Member States to formulate reservations on the African Children’s Rights Charter in accordance with the relevant international laws, particularly the Vienna Convention on the Law of Treaties of 1969’.42 Despite this decision, there can be comfort in that article 19(c) of the Vienna Convention on the Law of Treaties prescribes that reservations incompatible with the object and purpose of a treaty are invalid.43 As a result, it is difficult to make a legally valid argument to uphold some of the current, and potential future reservations to the African Children’s Rights Charter. In moving forward, these and related issues on reservations need to be addressed by the African Children’s Committee, in consultation with State parties. 4 EXAMPLES OF SUBSTANTIVE PROVISIONS This section highlights three provisions of the African Children’s Rights Charter that have added value to the implementation of children’s rights in Africa. These provisions are article 2 on the definition of a child, article 21(2) on child marriage, and article 22 on children and armed conflict. The effort is not to undertake an exhaustive analysis of these provisions, but to shed some light on what their strengths have been so far, and where appropriate, offer proposals on how the conceptualisation, interpretation and implementation of these provisions can be improved. 4.1 Definition of a child It would be incomplete to discuss children’s rights in connection with a child rights instrument, without first establishing who a child is. After all, the scope of application of the African Children’s Rights Charter is linked to the definition of a child. It is rightly argued that age is a criterion that can help to escape the ambiguities and contradictions of other definitions of a child, as it gives predictability regarding which rule or provision will apply to whom.44 Article 2 of the African Children’s Rights Charter offers a clear and concise definition of the child as ‘every human being under 18 years’ of 41 EX.CL/Dec.923(XXIX) Decision on the Report of the African Committee of Experts on the Rights and Welfare of the Child Doc. EX.CL/977(XXIX), para 3. 42 EX.CL/Dec.977(XXXI) Decision on the Report of the African Committee of Experts on the Rights and Welfare of the Child Doc.EX.CL/1033(XXXI), para 5. Article 2(1)(d) of the Vienna Convention on the Law of Treaties, allows State parties to international treaties to place reservations on provisions of a treaty they ratify or accede to. 43 Vienna Convention on the Law of Treaties, opened for signature on 23 May 1969. 44 See M Grahn-Farley ‘A theory of child rights’ (2003) 57 University of Miami Law Review 867.