巴拿马签证问题

各位大侠,请问我持有申根签证,到巴拿马要什么手续?在IATA网上是这样写的:
但是不明白,求帮助.
Visa required, except for A stay of max. 30 days, for holdersof: - normal passports endorsed "For Public Affairs", issued to nationals of China (People's Rep.).Visa required, except for A max. stay of 30 days for holdersof a valid visa issued by Andorra, Australia, Canada, Iceland,Monaco, Liechtenstein, Norway, San Marino, Switzerland, USA ora EU Member State For details, click here , provided having used the visaand traveling as tourist.Warning:- Visitors must hold return/onward airline tickets.- Nationals of China (People's Rep.) must hold an authorised stamped visa issued by the "Direccion Nacional de Migracion, Ministerio de Gobierno y Justicia, Departamento de Migracion

这句话是什么意思啊?provided having used the visaand traveling as tourist

还有这句,provided having used the visa and traveling as tourist
什么是USED?我的只是一次入境的申根签,但是我曾经有入境过的申根,这样可以吗?