1. From the evaluation expert system of the National Natural Science Foundation of China, it can be seen that in the fields of evaluation experts, personal information management and research, the first item is subject field. Open the edit field on the right, and you can see that the corresponding subject field is the application code.

2. When assigning evaluation experts, it is likely that they will be assigned according to the matching degree between the subject area of evaluation experts and the applicant's application code. Generally, judging experts will choose 5 to 10, while applicants only choose 2 application codes, so judging experts can cover the applicant's research direction in a wider range.

3. As can be seen from the above analysis, different application codes will have different experts. We know that different experts have different subjectivity, which will also lead to whether the state subsidizes them. Therefore, the application code largely determines whether the country receives funding.