Periodical, published regularly. Such as weekly, monthly, bimonthly, monthly, quarterly, biannual, annual, etc. Publications shall be published by periodical publishing units established according to law. Periodical publishing units must be approved by the General Administration of Press and Publication, hold a unified serial publication number in China, and obtain a periodical publishing license.
Broadly speaking, the classification of periodicals can be divided into informal periodicals and formal periodicals. An informal periodical refers to a periodical that is approved by the administrative department to receive the "internal newspaper approval" as an intra-industry communication (generally limited to intra-industry communication and not publicly issued), but it is also a legal periodical. Generally speaking, formal journals have gone through the process of informal journals.
Official periodicals shall be examined and approved by the Press and Publication Administration and the State Science and Technology Commission within the agreed number and incorporated into the "unified domestic serial number". The application for running a journal is relatively strict, which requires a certain publishing strength. Official periodicals have an independent publishing policy.
"Unified domestic serial number" is the abbreviation of "Unified domestic serial publication number", that is, "CN number", which is the code assigned to serial publications by the administrative department of press and publication. "International serial publication number" is the abbreviation of "international standard serial publication number", that is, "ISSN number", and most periodicals in China are equipped with "ISSN number".