To promote trade along these routes, Mongol authorities distributed an early type of combined passport and credit card. The Mongol paiza was a tablet of gold, silver, or wood larger than a man's hand, and it would be worn on a chain around the neck or attached to the clothing. Depending on which metal was used and the symbols such as tigers or gyrfalcons, illiterate people could ascertain the importance of the traveler and thereby render the appropriate level of service. The paiza allowed the holder to travel throughout the empire and be assured of protection, accommodations, transportation, and exemption from local taxes or duties.