CEDAW/C/GC/31-CRC/C/GC/18 IX. Treaty ratification or accession and reservations 90. States parties are encouraged to ratify the following instruments: (a) Optional Protocol to the Convention on the Elimination of All Forms of Discrimination against Women; (b) Optional Protocol to the Convention on the Rights of the Child on the sale of children, child prostitution and child pornography; (c) Optional Protocol to the Convention on the Rights of the Child on the involvement of children in armed conflict; (d) Optional Protocol to the Convention on the Rights of the Child on a communications procedure. 91. States parties should review and modify or withdraw any reservations to articles 2, 5 and 16, or their subparagraphs, of the Convention on the Elimination of All Forms of Discrimination against Women and articles 19 and 24 (3) of the Convention on the Rights of the Child. The Committee on the Elimination of Discrimination against Women considers reservations to those articles in principle incompatible with the object and purpose of the Conventions and thus impermissible under article 28 (2) of the Convention on the Elimination of All Forms of Discrimination against Women. 24/24 14-64765