Mirror Data refers to a methodology employed to access trade information for countries that do not publicly disclose their customs data. It involves utilizing the customs data provided by a country engaged in a trade transaction to deduce the trade activity of another country that does not disclose its customs data. For instance, if Country A trades with Country B and Country B divulges its customs data, the import data recorded by Country B can be utilized as a mirror representation of the export data from Country A. This approach relies on the availability of customs data from at least one of the countries involved in the trade, as it serves as a substitute for the undisclosed country's trade activity. However, it's important to acknowledge that if neither of the countries involved in the trade transaction discloses their customs data, the mirror data method cannot be applied.