First, the citation format does not meet the HowNet recognition standard.

The identification and citation content of HowNet detection system is that the reference documents meet the identification standards of HowNet. If the citation format of the reference is not standardized, the HowNet detection system may mark the reference in red to calculate the repetition rate, and will not detect the citation rate.

Second, the quoted content is too short.

If the citation content is too short, HowNet can't match the citation content, so it can't detect the citation rate.

3. The referenced content has been modified.

If the quoted text content has been modified, then the content you quoted cannot match the literature source of HowNet, and the modified article content may be considered original by HowNet.

4. The cited documents are not marked.

For hownet detection system, if you want to detect the citation rate, you must mark the cited documents and all the cited documents, otherwise the citation rate will not be detected (hownet detection system automatically recognizes very little).

5. The sources of references do not belong to HowNet.

If the source of the cited content does not belong to HowNet, HowNet cannot detect the citation rate.