Swiss patent law formerly allowed a patent application to be postdated if it was subsequently amended. In T 132/90 the patent proprietor had claimed 11.3.1983, the original filing date of the earlier Swiss application, as the priority date for his European application dated 9.3.1984. In 1985 the Swiss Patent Office ordered that the filing date of the Swiss patent application be set at 1.7.1983 following subsequent completion of the technical documentation. The board concluded that the original application should serve as the basis for claiming a priority right and that the priority date was the filing date of the original application. The postdating order did not take effect ab initio, and the subsequent fate of the original application was immaterial as far as the priority date was concerned.