The Protocol obliges States parties, among other things, to criminalize sexual exploitation of children; transfer of organs of children for profit; engagement of children in forced labour; offering, obtaining, procuring or providing children for child prostitution; and producing, distributing, disseminating, importing, exporting, offering, selling or possessing child pornography for the above purposes. International Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families 37. The International Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families currently has 21 States parties and entered into force in July 2003. It was developed by the United Nations in recognition of the great impact of flows of migrant workers on States and people concerned, and the need to develop norms which would contribute to harmonization of the attitudes of States through the acceptance of basic principles protecting migrant workers and their families. The Convention enumerates the basic rights of this particularly vulnerable group in human society and provides for the protection of those rights. Article 16 applies to migrant workers and their families many of the international standards concerning the right to liberty and security of person. Article 17 requires that migrant workers and members of their families who are deprived of their liberty be treated with humanity and with respect for the inherent dignity of the human person and for their cultural identity. Article 18 ensures that all migrant workers and their families have due process of law and equality with nationals of the State concerned before the courts, including the right to be presumed innocent until proven guilty according to law. International humanitarian law 38. For the purposes of training prison officials, international humanitarian law may be defined as the subset of human rights law applicable in times of armed conflict. The basic substance of humanitarian law is set out, article by article, in the four Geneva Conventions of 1949, which protect, respectively, the wounded and sick in the field; shipwrecked persons; prisoners of war; and civilian persons. The four Geneva Conventions currently have 189 States parties. 39. Additional sources include the two Additional Protocols of 1977 to the Geneva Conventions. Protocol I reaffirms and further develops the provisions of the Geneva Conventions with regard to international armed conflicts, while Protocol II does the same for conflicts which are internal, rather than international. Protocol I currently has 161 States parties and Protocol II has 156. 40. Under these instruments, international humanitarian law is to be applied in situations of armed conflict, during which principles of humanity are to be safeguarded in all cases. They hold further that non-combatants and persons put out of action by injury, sickness, capture or other causes must be respected and protected, and that persons suffering from the effects of war must be aided and cared for without discrimination. International humanitarian law prohibits the following acts in all situations: 13