What this means
Headings divide content into sections. Heading 1 is the main title, Heading 2 starts a section, and Heading 3 starts a smaller section inside it. Follow the levels in order when going deeper: do not jump from Heading 1 to Heading 3. A heading needs a real heading level; large or bold text alone is not enough.
Passing examples
- Heading 1: Visiting us. Heading 2: Getting here. Heading 3: By train. Each smaller section sits under the right parent.
- Heading 2: Services, followed by Heading 2: Prices. Both sections are at the same level, so the repeated level is correct.
- Heading 2: Getting here. Heading 3: By train. Heading 3: By bus. Heading 2: Opening hours. Returning to Heading 2 correctly starts a new main section.
- A document's title uses Heading 1 and its main sections use Heading 2. Reading software recognizes the headings, not just their appearance.
Failing examples
- Heading 1: Visiting us is followed directly by Heading 4: Getting here. Levels 2 and 3 have been skipped.
- A section uses Heading 2, but its first subsection uses Heading 4. Heading 3 is missing.
- A line looks like a heading because it is large and bold, but it is still an ordinary paragraph with no heading level.
- 'By train' and 'By bus' are equal subsections, but one is Heading 3 and the other is Heading 5 just to make it smaller.
Returning from Heading 3 to Heading 2 is fine: it ends the smaller section. These principles apply to web pages, documents, and any publishing tool that supports headings.