UNICEF, Innocenti Research Centre, Handbook on the optional protocol on the sale of children, child prostitution and child pornography, 2009-02, p. viii ([Internet, 2023-02-28](https://www.unicef-irc.org/publications/pdf/optional_protocol_eng.pdf))
Trafficking of children is most often connected to the sale of children, child prostitution and child pornography, as well as to child labour, child soldiering, illegal adoption and other forms of exploitation.