1, international standard serial publication number ISSN, domestic unified serial publication number CN (abbreviated as China). ISSN (International Standard Serial Number) is an international standard code for continuous publications based on the international standard ISO3297. Its purpose is to make every serial publication with different titles and versions in the world have an international unique code identification.

2. This number is prefixed by ISSN and consists of 8 digits. The 8-digit number is divided into two sections, each with 4 digits, and the middle is connected by connecting digits. The format is as follows:

ISSNXXXX-XXXX

3 "periodical classification number" and "periodical category" are the classification numbers of China unified serial publication number. For example, the domestic unified serial publication number of Shandong Pictorial is CN37- 1038/Z, and the "periodical category" code is "Z".

4. The classification numbers of various periodicals are as follows: A: Marxism-Leninism, Mao Zedong Thought, Deng Xiaoping Theory B: Philosophy, Religion C: Introduction to Social Sciences D: Politics, Law E: Military F: Economy G: Culture, Science, Education, Sports G0: Comprehensive Culture G 1: Cultural and Cultural Undertakings of Countries in the World G2: Information and Knowledge Dissemination G3: Science and Research.