A number of headings for pages are duplicated (but different case). I guess the page has a top level heading and a page title from the URL.

E.g.:

html, HTML: http://docs.webplatform.org/wiki/html 
css, CSS Reference: http://docs.webplatform.org/wiki/css
svg, SVG Reference: http://docs.webplatform.org/wiki/svg
javascript, JavaScript: http://docs.webplatform.org/wiki/javascript
accessibility, Accessibility Basics: http://docs.webplatform.org/wiki/concepts/accessibility
concepts, concepts basics: http://docs.webplatform.org/wiki/concepts

If the second of the two are kept, they should probably be consistant, at least for the technology pages. Either include Reference or not.