Shorter headings are usually better, especially for web content. However, headings should provide a meaningful description of the content to follow, so should be long enough to provide clear information on the section’s contents. Try to start headings with keywords, not articles like ‘the’ or ‘an’ (see Writing informative headings for more information).
Use minimal capitalisation in headings (ie initial capitals only for the first word and any proper nouns); full capitals are hard to read. Do not underline headings, since this is also hard to read, and may be mistaken for a hyperlink in online documents:
How to grow your own vegetable garden
not
HOW TO GROW YOUR OWN VEGETABLE GARDEN
How To Grow Your Own Vegetable Garden
How to grow your own vegetable garden
The structure of headings should be parallel (see Using parallel structure). For example, if most headings are statements and one is a question, the question should be changed to a statement to be parallel with the others.
Use styles in Microsoft Word or your chosen word-processing program to format headings. This will ensure that the paragraph style is consistent and make it easy to create a table of contents. Using paragraph styles is also important for accessibility.
Make sure you clearly differentiate the heading styles from one another. Using a clear progression of font styles from more to less prominent helps your audiences see the structure of the document. Some ways to differentiate headings include font size, italics, bold, and space above and below the heading:
Often, subsection headings are numbered. Do not include a final stop after the numbers (ie use ‘1.1.1 Heading’, not ‘1.1.1. Heading’), and avoid numbering headings below heading level 3 (ie do not use ‘1.1.1.1 Heading’). However, some specific types of documents (eg some legal documents) may require numbering right down to the level of individual paragraphs: