This code has no practical significance, just a machine code of a subject, which is convenient for machine identification. It is of no use except convenience. In order to facilitate data entry and indexing, account codes are used to represent accounts. Never mind the code, just look at the exam subjects. For example: 1 10 1 politics 220 1 English 30 1 math 1 302 math 2 303 math 3 304 math 4 www.kaoyan.cn.