1. This subtitle is a first-class title. (1) This subtitle is a secondary title. 1. This title is a third-class title, and (1) this title is a fourth-class title.

1.(1)1.(1) These are called article subtitles, which are generally suitable for formal official document writing, such as graduation thesis of college students and articles published by formal institutions.

Correct use of serial numbers and punctuation marks in written materials

1, first, second, third or first, second, etc. None of them are standardized. Use commas, that is, first, second, third, first and second.

2. There is no need for punctuation marks in the first part, the first chapter, the first section or after the first section, and a Chinese character position can be left between them, such as "the first section measurement method".

3. It is not standard to use commas after the numbers "one", "two" and "three" in Chinese characters, but to use pause, "one", "two" and "three".

4. When Arabic numerals "1", "2", "3", "a", "b" and "c" are followed by pauses (",") or other irregularities, ink dots (solid dots ",") aligned with lines should be used, namely "1" and ".