How to mark serial publication numbers?

The front part of the domestic unified serial publication number consists of prefix CN and 6 digits. The national publishing management department assigns six digits to continuous publications. There is half a Chinese character blank between CN and 6 digits. The first 2 digits and the last 4 digits of 6 digits are separated by a half word line. A) The first two digits of the 6 digits of the domestic unified serial publication number are the area number, which is given according to the first two digits of the number code in GB/T 2260 (see Appendix B). In Beijing, where there are many serial publications, when the area code "1 1" is used up, the serial publications in Beijing use "10" as the spreading code. B) The last four digits of the six digits of the domestic unified serial publication number are the serial numbers of regional serial publications. The serial numbers of domestic serial publications in all provinces, autonomous regions and municipalities directly under the Central Government range from 000 1 to 9999', of which 000 1 to 0999 is the newspaper serial number, 1000 to 5999 is the printing serial number, 6000 to 8999 is the network serial number, and 9000 to 9999.