13 refers to plagiarism, because the general article types are checked by the school duplicate checking system, and the duplicate checking rule of HowNet is 13, so neither the quoted content nor the text content can be duplicated with the document content exceeding 13 in the database, otherwise it will be included in the duplicate checking rate. Moreover, there are other duplicate checking rules in the school duplicate checking system, and the threshold is set at 5%. Papers will be marked red as long as the cited part exceeds 5%; At present, the duplicate checking system still can't detect the contents of the chart. The school duplicate checking system does not copy charts, but it also copies formulas, so it is best to edit them with mathtype when writing. The citation of references should pay attention to the correctness of the format and need to be quoted in quotation marks; The content and appendix should also be written correctly, and only the correct writing format will not be repeated.