Points for Consideration
188.8.131.52 Creating an outline
There are currently no known implementations of the outline algorithm in graphical browsers or assistive technology user agents, although the algorithm is implemented in other software such as conformance checkers. Therefore the outline algorithm cannot be relied upon to convey document structure to users. Authors are advised to use heading rank (h1-h6) to convey document structure.
Source: 4.3. HTML5 Outlines
Why we care about outlines.
Document outlines rely on heading structure, and this was and is used to generate outlines for assitive technology.See the results of an earlier webaim survey here. Screen Reader Survey #5 (2014) 65% of Respondents use headings to navigate through the page.
Does the HTML5 header element help?
The HTML5 header element does not take part in the outline algorithm. The header element is not sectioning content; it doesn't introduce a new section.Link to the W3C reference
What about HTML5 and the h1 tags?Why we are told that using multiple h1 tags is GOOD
Why we are told using multiple h1 tags is BAD
- Conformance and Validation are not the same thing.
- There are differences between the w3c validator and the nu markup checker.
- There are differences between W3C HTML and WHATWG HTML conformance.
- DTD and Schema are not equivalent.