Mexico's green card has prepared a piece of paper. What is this?

Voucher. According to the inquiry of the World Wide Web, the green card will be accompanied by an identity certificate, which records the personal information, entry date, category and other important information of immigrants. United MexicanStates (Spanish: EstadosUnidosMexicanos, English: United Mexico), with a land area of1964,400 square kilometers, is the third largest country in Latin America, ranking 14 in the world, located in the south of North America and at the northwest end of Latin America. The whole country is divided into 32 states.