The day after the collapse of the Soviet Union, Gorbachev handed over the "secret archives" to Yeltsin. This secret file was originally stored in the sixth place of the Soviet General Affairs Department, and later transferred to the Soviet archives. 1990, after the Soviet Union implemented the presidential system, this file was kept in the presidential palace of the Kremlin and kept by Gorbachev.
According to Gorbachev's memory, even Gorbachev didn't know what information was stored in this sealed file, so he printed a "never open" ban on the file cover. But the core leadership of the Soviet Union can read it. Before and after the disintegration of the Soviet Union, Gorbachev was busy with the disintegration of the Soviet Union and didn't care about such an ancient file.
Although the sealed files are stored in the presidential archives, archivists have no right to read them unless Gorbachev approves them under special circumstances. But such a "special situation" will not appear at all.
Gorbachev handed over the nuclear button on the night of the disintegration of the Soviet Union, and handed over some secret documents he and Yeltsin kept together the next day, including this "secret volume" locked in Gorbachev's locker.
During the handover, besides Gorbachev and Yeltsin, Jakovleff was also present. Gorbachev admitted that when he handed over power to Yeltsin, he also handed over the sealed document and they read the contents of the document together.
When this file was handed over, people in the president's office still had doubts and thought it was unnecessary to open this sealed file again. But when Gorbachev and Yeltsin handed over in the oval office, the sealed documents were opened. After Gorbachev knew about it, he also told Poland at the first time, and finally Poland also knew about it.