On vic.gov.au the most commonly used headings are Heading 2 and Heading 3.

Highlight your heading and click on Format and select your heading style.

The first heading after the title must be Heading 2 (because the page title is formatted as Heading 1)

The next subheading must be Heading 3 (you can’t jump from 2 to 4 for example, just because you like the way it looks).

Learn more about Headings on the Style Manual:

• Write headings that are clear and short

• Use keywords to start headings

• Organise heading levels in a logical order

• Be consistent: use a parallel structure

• Use unique formatting for each level of heading

• Write all headings in sentence case and use minimal punctuation