First of all, different schools or institutions may have different requirements for paper duplicate checking rate. Generally speaking, schools or institutions will determine the standard of duplicate checking rate according to the field of papers, the type of research and the quality requirements of publications. For example, in some fields, such as medicine or law, the duplicate checking rate of papers may be very low, only 5% or less. In other fields, such as social science or humanities, the requirement of duplicate checking rate may be higher, between 20% and 30%.

Secondly, different types of papers may have different requirements for duplicate checking rate. For example, the duplicate checking rate of academic papers is usually stricter than graduation papers or course papers. In addition, some specific types of papers, such as doctoral papers or periodical papers, may have stricter requirements on duplicate checking rate.

Finally, it should be noted that even if the school or institution does not clearly stipulate the duplicate checking rate, the author should try to reduce the duplicate checking rate. This is because in the academic field, repetition or plagiarism is strictly prohibited. If the paper is found to be duplicated or plagiarized, the author may face serious academic punishment or even be expelled.

Therefore, in order to ensure the quality and academic integrity of the paper, the author should reduce the duplicate checking rate of the paper as much as possible. Generally speaking, for most schools or institutions, the duplicate checking rate of papers is acceptable between 10%-30%. However, for some specific fields or types of papers, the requirement of duplicate checking rate may be more stringent. Therefore, the author should carefully read the relevant regulations of the school or institution to ensure that his paper meets the requirements.