The knowledge of distinguishing foreign stamps is a profound knowledge. More than 200 countries and regions in the world have issued stamps, including the types of stamps, paper, perforations, anti-counterfeiting marks, etc. Very different. Except some countries with more stamps (such as the former Soviet Union, Hungary, North Korea, etc. ), other countries and regions are generally difficult to identify. Some experienced stamp collectors collect foreign stamps first by experience and then by help. It is recommended to go to a bookstore or mail order books about foreign mail, such as