According to my comment on T13555, section HTML output should looks as follows:

<section>
<header>
<h2>Section heading</h2>
<span>[edit section]</span>
</header>
<p>Bunch of awesome content</p>
</section>

See its specification on https://developer.mozilla.org/en-US/docs/Web/HTML/Element/section and http://www.w3schools.com/tags/tag_section.asp

See also: https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Sections_and_Outlines_of_an_HTML5_document

Version: 1.23.0
Severity: enhancement

• This bug was marked as a duplicate of T8104 at some point.

See also

• T49936: Implement <section> natively in Parsoid, possibly as plain HTML5 content
• T53562: <section> in text content is not nowiki-escaped
• T32597: <section> tag name collides with HTML5 <section> tag

Related:

• T12467: Use semantic HTML (tracking)
• T13555: .mw-editsection links should not be part of the <h#> element