Administrative Instructions under the Patent Cooperation Treaty

Section 307
System of Numbering International Applications

Papers purporting to be an international application under Rule 20.1(a) shall be allocated an international application number, consisting of the letters "PCT," a slant, the two-letter code referred to in Section 115, indicating the receiving Office, a four-digit indication of the year in which such papers were first received, a slant and a six-digit number, allotted in sequential order corresponding to the order in which the international applications are received (e.g., "PCT/SE2004/000001"). Where the International Bureau acts as receiving Office, the two-letter code "IB" shall be used.