The maincontent element

Categories:
Flow content.
Palpable content.
Contexts in which this element can be used:
As a child a body element containing no other maincontent elements.
As a child of a div element that is the child of 0 or more div elements that are children of a body element containing no other maincontent elements.
 
Content model:
Flow content.
Content attributes:
Global attributes
DOM interface:
Uses HTMLElement.
The maincontent element represents the main content section of the body of a document or application. The main content section consists of content that is directly related to or expands upon the central topic of a document or central functionality of an application.

The main content section of a document should include content that is unique to that document and excludes content that is repeated across a set of documents such as site navigation links, copright information, site logos and banners and search forms (unless the document or applications main function is that of a search form).

In conforming documents, there is only one maincontent element.

The maincontent element formalises the common practice of identification of the main content section of a document using the id values 'content' and 'main'. It also defines an HTML element that embodies the semantics and function of the WAI-ARIA landmark role=main.

In the following example, we see 2 articles about apples (the main topic of a Web page) the main topic content is identified by the use of the maincontent element.

<!-- other content -->

<maincontent>

  <h1>Apples</h1>
 <p>The apple is the pomaceous fruit of the apple tree.</p>
  <article>
 <h2>Red Delicious</h2>
  <p>These bright red apples are the most common found in many
  supermarkets.</p>
  </article>

  <article>
  <h2>Granny Smith</h2>
  <p>These juicy, green apples make a great filling for
  apple pies.</p>
  </article>

</maincontent>

<!-- other content -->

Here is a graduation programme the main topic content is defined by the use of the maincontent element.

<!DOCTYPE html>
<html>
<head>
<title>Graduation Ceremony Summer 2022</title>
</head>
<body>

<!-- other content -->

<maincontent>

<h1>Graduation</h1>

<H2>Ceremony</H2>
<p>Opening Procession</p>
<p>Speech by Validactorian</p>
<p>Speech by Class President</p>
<p>Presentation of Diplomas</p>
<p>Closing Speech by Headmaster</p>

<h2>Graduates</h2>
<ul><li>Molly Carpenter</li>
<li>Anastasia Luccio</li>
<li>Ebenezar McCoy</li>
<li>Karrin Murphy</li>
<li>Thomas Raith</li>
<li>Susan Rodriguez</li>
</ul>

</maincontent>

<!-- other content -->

</body>
</html>

Notes

From publically reported studies [1] of id values used in HTML content, the use of the strings "content" and "main" are common practice.

[1] http://triin.net/2006/06/12/CSS#figure-34, http://westciv.typepad.com/dog_or_higher/2005/11/real_world_sema.html