A/HRC/15/29 5. As human mobility, including child mobility, has become more complex, movements can include elements of the search for protection entwined with the search for opportunity. Often these motivations will change along the migratory route, shifting children from one category to another. The challenge for the formulation and implementation of policy is to ensure that such categorization does not impede a human rights-based response to the assistance and protection needs of children in the context of migration. This report will concentrate on the international movement of migrant children in view of their particular vulnerability as non-nationals, while recognizing that a far greater number of children move within their countries, as internally displaced persons and internal migrants.9 6. Asylum-seeking and refugee children have particular international protection needs which must be identified and addressed. At the same time, it is necessary to bear in mind that children can have, and can acquire in the course of movement, a need for protection that is different from refugee status, but that is no less important. It is critical also to recognize and address in policy and practice the particular vulnerability of girl children to violence and discrimination within the context of migration. 7. Children are affected by migration in various ways: children are left behind by one or both parents who migrate; they accompany their migrating parents; and they migrate alone, independently of parents and adult guardians. Some children return to their countries of origin, either voluntarily or as the result of force. There are unfortunately limited statistics on the global movement of children10 and this lack of disaggregated data is one of many challenges in formulating and implementing child-sensitive migration policies.11 8. Both immigration and child-protection12 legislation are employed to deal with the issue of migrant children. However, these standards are sometimes applied in a confusing 8 9 10 11 12 4 Organized Crime). Smuggling has been distinguished from trafficking and is defined as “the procurement in order to obtain, directly or indirectly, a financial or other material benefit of the illegal entry of a person into a State Party of which the person is not a national or a permanent resident” (art. 3(a), Protocol against the Smuggling of Migrants by Land, Sea and Air, supplementing the United Nations Convention against Transnational Organized Crime). Unaccompanied children “have been separated from both parents and other relatives and are not being cared for by an adult who, by law or custom, is responsible for doing so”; separated children “have been separated from both parents, or from their previous legal or customary primary caregiver, but not necessarily from other relatives. These may, therefore, include children accompanied by other adult family members”. (Committee on the Rights of the Child, general comment No. 6 on treatment of unaccompanied and separated children outside their country of origin). Such children will require specific protection in the context of their displacement. See United Nations Development Programme (UNDP), Overcoming barriers: Human mobility and development, Human Development Report 2009 (Basingstoke and New York, Palgrave Macmillan, 2009). The recent report of the Special Rapporteur on the human rights of migrants notes that “there is no accurate statistical information on the number of children involved in the international migration process. Age is not a common variable of disaggregated statistical data on international migration” (A/HRC/11/7, p. 5). See Jeronimo Cortina and Bela Hovy, “Boosting Cooperation: UNICEF, UNDESA and SU/SSC Joint Studies on Migration”, South-South in Action, vol. summer 2009, pp. 3–5 (MediaGlobal, 2009). A child protection system comprises a set of laws, policies, regulations and services, in particular services related to social welfare, education, health, security, labour and justice. Given that such a system requires the input and actions of a wide variety of public authorities, in addition to private actors such as NGOs, the issue of coordination is both an imperative and a significant challenge in practice. In the case of migration policies, this is further complicated by the need to ensure that there is coordination across international borders.