On January 1, 2007 (November 13, 2006 lunar calendar), the international standard book number (ISBN) was changed from 10 digits to 13 digits. On January 1, 2007, the international standard book number (ISBN) was changed from 10 digits to 13 digits. On January 1, 2007, the fourth edition of the "International Standard Book Number (ISBN) " was officially implemented. The number of digits of the standard book number was raised from the original 10 digits to 13 digits. The revised "China Standard Book Number" added the display method and printing position regulations of the book number, and included the allocation and use principles of the Chinese standard book number in the standard. The scope of use of Chinese standard book numbers has been expanded, and non-print publications such as electronic publications have also been included in the scope of use. The international standard book number (ISBN) was identified as an international standard by the international standardization organization in 1970 and has now been used by publishers in more than 160 countries and regions.