In 1992, the United States and China signed a memorandum of understanding (MOU) to allow administrative protection (AP) in China for US pharmaceutical patents granted between 1986 and 1992. The MOU provided seven-and-a-half years of market exclusivity, or AP rights, in China for pharma patents that were: not protected by exclusive rights before the amendment of current Chinese laws; patent protected after 1 January 1986 and before 1 January 1993 in an MOU signatory country; not previously marketed in China. Several Chinese government policies have prevented US industry from realizing the intended MOU benefits. According to Article 42 of the Patent Law, the duration of patent right for inventions is twenty years, and the duration for utility models and patent right for designs is ten years, counted from the date of filing.