Headings and subheadings in the body of your research project can help organize and structure your writing, but you should avoid overusing them. Headings should never be used to compensate for poor structure or to explain an underdeveloped idea, and they are generally not needed in short, essay-length works. When headings are called for in your writing project, keep them short and observe the basic guidelines below.

Consistency in the styling of headings and subheadings is key to signaling to readers the structure of a research project. Word processing software often has built-in heading styles. Headings in the body of your research project should be styled in descending order of prominence. After the first level, the other headings are subheadings—that is, they are subordinate. Font styling and size are used to signal prominence. Each level 1 heading should appear in the same style and size, as should each level 2 heading, and so on. In general, a boldface, larger font indicates prominence; a smaller font, italics, or lack of bold can be used to signal subordination. For readability, avoid using all capital letters for headings (in some cases, small capitals may be acceptable).

No internal heading level should have only one instance. For example, if you use a level 1 heading, you should have at least one other level 1 heading. (The exceptions are the paper or chapter title and the headings for notes and the list of works cited.)

In the body of the paper, headings should be flush with the left margin, not indented or centered. For readability, include a line space above and below a heading.

Generally avoid using numbers and letters to designate headings unless you are working in a discipline where using them is conventional.

Capitalize and punctuate headings like the titles of works as explained in 2.90–2.119.