We use Section 508 as a guideline for accessibility. In particular, semantic naming and proper source hierarchy are used, with valid markup. Also, the dropdown menu is keyboard navigable and functional without Javascript enabled, and links are highlighted on :focus. There is also a skip-to-content link as the first link in the source order that becomes visible when activated. When text is replaced with images, it is moved off-screen rather than hidden so that it is legible by screenreaders. In addition, care is taken to ensure that text is resizeable as much as possible without breaking the layout, for those with visual disabilities.

However, most of the burden for accessiblity in Drupal is on what goes into the content added to the site, or features supported by additional modules. For example, images in nodes or blocks should have alt text, and videos should have transcripts or subtitles"