1. If ISBN is 13 digits, the leading digit of GS 1 is usually 978 or 979[ 1].
2. Publish country or language codes.
3. Publisher code.
4. The number assigned to the book.
5. Check the code.
The international standard number of 13 code is usually divided into five parts (10 code is four parts), and different parts are clearly separated by hyphens-or spaces, and the number of digits can be changed, and the hyphens can be ignored when the system processes; The leading number ensures that this string of numbers can be judged as an international standard book number. If necessary, the hyphen must be correctly marked; They can let users clearly judge the relationship between numbers and publishers and their countries. The International Standard Book Number Catalogue (PIID) is an unfixed periodical publication.
In the past, SBN had no country and language codes. After ISBN appeared, the country code of books published in the United States was 0. 1 is an English-speaking country and 2 is a French-speaking country; 3 is a German-speaking country, 4 is Japanese, 5 is suitable for Russian-speaking countries, 7 is Chinese mainland and so on. The longest country field may be five digits (for example, Bhutan is 99936), but the remaining digits that can be used and allocated are narrower.
ISBN, which is responsible for national and international standards, will allocate its digit range according to the size of publishers, who can have their own codes. ISBN is not mandatory to be printed on the book, but it is generally printed on the copyright page and the bar code at the bottom of the book.
After the application, the publishing house can be assigned to a digital area of the international standard book number. According to the usage, the organization will predict the range of publishers' needs and allocate them. The bigger the publishing house, the smaller the number of digits (that is, the range of ISBN can accommodate more). Once it is found that the allocated digital area is not enough, the publisher can allocate another area for its use, that is, get another publisher number. Therefore, the number of international standard numbers of various countries and publishing houses will be well distributed because of their status.