Heading

HTML element (h tag) with 6 levels of hierarchy (from h1 for the most important heading to h6 for the least important) or HTML element with WAI-ARIA role="heading" and aria-level attributes used to structure the information in web content.

Ensuring a strict hierarchy between the headings of a web page is good practice, but the presence of hierarchical jumps does not invalidate the criterion as long as this looser hierarchy remains consistent (a <h3> heading can come directly after a <h1> heading, for example). The headings hierarchy does not have to contain a <h1> heading. Although these practices are not encouraged, they do not invalidate the criterion.

Note: headings visually hidden via CSS are considered to be present and validate the critère 9.1.