such charges may be required to be made by the affixture and cancellation of documentary stamps. Among the charges which may be thus fixed are these: pilot fees, fees for the admeasurement of vessels, the fees incident to the registration or copying of documents in the exercise of the function of commercial register, and such other charges as may be p roper in connection with the performance of the duties pertaining to the office of captain of port. [355-393.] SECTION  1567 . Effect of Failure to Stamp Document . — An instrument, document, or paper requiring a stamp or stamps as provided in this article shall not be received or recognized by any customs official, or admitted as evidence in any court of law, or be h eld valid for any purpose until the requisite stamp or stamps have been affixed thereto and properly canceled. [1341-4.] SECTION  1568 . Tonnage Dues on Vessels Engaged in Philippine Trade . — There shall be collected at all ports and places in the Philippine Islands from any vessel coming from or going to a port or place outside of the territory of the Philippine Islands, irre spective of nationality, twelve and one-half centavos per net ton as expressed in her certificate of registry, or thirty-five centavos per thousand kilograms of merchandise discharged or laden, in Philippine ports, at the option of the master or consignee  of the vessel. [2579.] SECTION  1569 . Vessels Exempt from Tonnage Dues . — The following shall be exempted from the payment of the dues herein established: ARTICLE  XXII Tonnage Dues ( a ) Vessels not discharging or lading cargo and discharging and lading only passengers and their baggage; ( b ) Vessels belonging to the Government of the United States and to foreign governments, or chartered by the same, if not engaged in trade; ( c ) Vessels in distress; and Copyright 2012 CD Technologies Asia, Inc. and Accesslaw, Inc. Philippine Law Encyclopedia 2011 460