Headings are key to web accessibility. Relevant WCAG criteria are 1.3.1 (information and relationships), 2.4.6 (descriptive headings), 2.4.1 (bypass blocks) and 2.4.10 (section headings). A best-practice checklist is included, along with tools like HeadingsMap to test heading structure.

CSS pseudo-elements :before and :after are read inconsistently by screen readers: some verbalise them, others do not. They should only be used for decorative visual content that is harmless if read aloud. Relevant content must never be added exclusively through these pseudo-elements.

HTML5 offers an accessible alternative to Flash for dynamic content, but browsers still have uneven support. The site html5accessibility.com regularly tracks the accessibility status of browsers for HTML5. Currently, Firefox for Windows and Safari for Mac are the most recommended options.