h6 elements may have the
outlinemask content attribute set. The
outlinemask attribute is a boolean attribute. When specified on one or more
h6 elements,it indicates that the element is not to be included in the document outline. User agents should not include the
h6 elements or their content in the document outline if the
outlinemask attribute is specified.
outlinemask IDL attribute must reflect the content attribute of the same name.
The ARIA role mapping for a
h6 element that has an
outlinemask attribute is the same as a
h6 element without an
outlinemask attribute set.
User agents MAY provide an indication that a heading is a subheading when the attribute is set.
Here are some examples of valid use of the
outlinemask attribute. In each case, the
subline content represents the text that is a subheading, subtitle,
tagline or byline of a heading. The
subline content would not be used as a
heading in an application extracting heading data and ignoring
<h1>The reality dysfunction</h1> <h2 outlinemask>Space is not the only void</h2>
<h1>Dr. Strangelove</h1> <h2 outlinemask>Or: How I Learned to Stop Worrying and Love the Bomb</h2>
Assistive technology may convey the semantic of the
outlinemask attribute instead of the heading it is on. Thus for an assistive technology user the first example above could be announced as:
"heading level 1 The reality dysfunction subheading Space is not the only void"
Or the assistive technology may convey both the heading and outlinemask semantics.
"heading level 1 The reality dysfunction subheading, heading level 2 Space is not the only void"
Or the assistive technology may convey only the heading semantics.
"heading level 1 The reality dysfunction, heading level 2 Space is not the only void"
The element in the following list is an addition to those defined as obsolete in HTML5, is entirely obsolete, and must not be used by authors:
To identify sub headings Use the