"The copyright of commissioned works [has] important contract terms. The nature of the ownership of copyright agreement is related to the client to obtain the copyright, the trustee obligations and the balance of the interests of both sides. The client gets the copyright through the commissioned works contract that is called achieving by the following. As a result of the invisible works and lack of copyright registration system , the Trustee fulfills his obligation by the legal presumption of copyright transfer. The transfer of the copyright happens with the creation of the commissioned works. The writing contract of the Commissioned works often becomes public means of copyright transfer. Payment from the client and the copyright transfer from the trustee constitute the consideration that impacts copyright transfer."
Read Xu's article here (pdf in Chinese). Picture Danny Friedmann, Yangshuo, Guangxi Province.