1. Paper duplicate checking mainly checks the abstract, keywords, text, quotations and other contents of the paper, but most paper duplicate checking systems cannot duplicate non-text contents such as formulas, charts and so on, because the system has not developed such incomparable technology.

Second, for the reference, that is, the part cited in the paper, it is generally checked whether it is marked according to the standard format. If the format is incorrect, the repetition rate can be calculated. If you quote too much, some content may be judged as plagiarism.

Thirdly, the paper duplication detection is mainly aimed at words, which generally can't detect the meaning of sentences, but the paper duplication detection system can identify the semantics according to the sentence context, that is, if only a few words are modified, the paper duplication detection may also be judged as repeated plagiarism.

Fourthly, in the process of paper duplicate checking, you can check the duplicate papers more accurately by entering your real name, because some paper duplicate checking systems will check the published papers of the author according to the author's name, then delete these published papers and calculate the repetition rate of published papers, so that the duplicate checking results are more accurate.