Sealing a file means that the file materials will not be made public, inquiries and access will be restricted, and copies will not be allowed. According to the law, archival materials formed in cases involving confidential or special information that should not be disclosed as well as cases involving minors' crimes shall not be disclosed for the sake of national security, privacy protection, social public interests and the protection of the rights and interests of minors. If it is not disclosed to the public for legal reasons and is investigated and understood by legal personnel in accordance with the law, the case file materials will be more strictly kept and managed.