Sectioning content
Sectioning content is content that defines the scope of headings and footers.
+ content">headings and footers, and determines the + heading level ofh1 and hgroup elements.
-
@@ -10969,13 +10969,7 @@ console.assert(image.height === 200);
section
Each sectioning content element potentially has a heading and an - outline. See the section on headings and sections for further - details.
- -There are also certain elements that are sectioning - roots. These are distinct from sectioning content, but they can also have an - outline.
+See the section on headings and sections for further details.
Heading content
@@ -15462,7 +15456,7 @@ interface HTMLStyleElement : HTMLElement {- Categories: -
- Sectioning root. +
- None.
- Contexts in which this element can be used:
- As the second element in an
htmlelement. - Content model: @@ -15735,8 +15729,8 @@ interface HTMLBodyElement : HTMLElement {
- Uses
HTMLHeadingElement.
- - Uses
HTMLElement.
The section element is not a generic
container element. When an element is needed only for styling purposes or as a convenience for
scripting, authors are encouraged to use the div element instead. A general rule is
- that the section element is appropriate only if the element's contents would be
- listed explicitly in the document's outline.
section element is appropriate when used in conjunction with a heading.
These elements represent headings for their sections.
-The semantics and meaning of these elements are defined in the section on headings and sections.
-These elements have a rank given by the number in their name. The h1
- element is said to have the highest rank, the h6 element has the lowest rank, and two
- elements with the same name have equal rank.
As far as their respective document outlines (their heading and section structures) are - concerned, these two snippets are semantically equivalent:
+As far as their respective heading levels are concerned, + these two snippets are semantically equivalent:
<body>
<h1>Let's call it a draw(ing surface)</h1>
@@ -16263,7 +16250,7 @@ interface HTMLHeadingElement : HTMLElement {
The two styles can be combined, for compatibility with legacy tools while still
future-proofing for when that compatibility is no longer needed. This third snippet again has the
- same outline as the previous two:
+ same heading levels as the previous two:
<body>
<h1>Let's call it a draw(ing surface)</h1>
@@ -16283,12 +16270,10 @@ interface HTMLHeadingElement : HTMLElement {
<h2>Paths</h2>
</section>
</body>
-
The hgroup element
-
@@ -16308,24 +16293,15 @@ interface HTMLHeadingElement : HTMLElement {
The hgroup element represents the heading of a section, which
- consists of all the h1–h6 element children of the
- hgroup element. The element is used to group a set of
- h1–h6 elements when the heading has multiple levels, such as
- subheadings, alternative titles, or taglines.
The hgroup element can be used to group a set of
+ h1–h6 elements for a heading that has multiple levels, such as subheadings, alternative
+ titles, or taglines.
The rank of an hgroup element is the rank of the highest-ranked
- h1–h6 element descendant of the hgroup element, if
- there are any such elements, or otherwise the same as for an h1 element (the highest
- rank). Other h1–h6 elements of heading content in the
- hgroup element indicate subheadings or subtitles or (secondary) alternative
- titles.
The section on headings and sections defines how hgroup elements are
- assigned to individual sections.
The remainder of the semantics and meaning of the hgroup element, including what
+ it represents, are defined in the section on headings and sections.
Here are some examples of valid headings.
<hgroup>
@@ -16338,14 +16314,12 @@ interface HTMLHeadingElement : HTMLElement {
<h2>Or: How I Learned to Stop Worrying and Love the Bomb</h2>
</hgroup>The point of using hgroup in these examples is to prevent the h2
- element (which acts as a secondary title) from creating a separate section of its own in any
- outline and to instead cause the contents of the h2 to be shown in
- rendered output from the outline algorithm in some way to indicate that it is not
- the title of a separate section but instead just a secondary title in a group of titles.
The point of using hgroup in these examples is to create a single heading
+ consisting of two pieces (the primary title in the h1 element and the secondary
+ title in the h2 element).
How a user agent exposes such multi-level headings in user interfaces (e.g. in tables of +
How a user agent exposes such multi-level headings in user interfaces (e.g., in tables of contents or search results) is left open to implementers, as it is a user interface issue. The first example above could be rendered as:
@@ -16360,7 +16334,6 @@ interface HTMLHeadingElement : HTMLElement {The reality dysfunction Space is not the only void-
h1 gives
the (primary) title while the second gives the (secondary) alternative title. Even though both
the title and alternative title are marked up with h1 elements, in a rendered view
- of output from the outline algorithm, the second h1 in the
- hgroup will be shown in some way that clearly indicates it is secondary; for
- example:
+ the second h1 in the hgroup will likely be shown in some way that
+ clearly indicates it is secondary; for example:
In a US publication:
The Avengers (Avengers Assemble)
In a UK publication:
Avengers Assemble (The Avengers)-
In the following example, an hgroup element is used to mark up a two-level
heading in a wizard-style dialog box:
The header element is not sectioning content; it doesn't
- introduce a new section.
The header element is not sectioning content.
In this example, the page has a page heading given by the h1 element, and two
- subsections whose headings are given by h2 elements. The content after the
- header element is still part of the last subsection started in the
- header element, because the header element doesn't take part in the
- outline algorithm.
Another example header for a game:
<body>
<header>
@@ -16508,15 +16471,12 @@ Space is not the only voidThe footer element represents a footer for its nearest ancestor
- sectioning content or sectioning root element. A footer typically
- contains information about its section such as who wrote it, links to related documents, copyright
- data, and the like.
body element. A footer typically contains
+ information about its section, such as who wrote it, links to related documents, copyright data,
+ and the like.
When the footer element contains entire sections, they represent appendices, indexes, long colophons, verbose license
@@ -16558,11 +16518,10 @@ Space is not the only void
Footers don't necessarily have to appear at the end of a section, though they usually do.
-When the nearest ancestor sectioning content or sectioning root - element is the body element, then it applies to the whole page.
+When the nearest ancestor sectioning content or body element is
+ the body element, then it applies to the whole page.
The footer element is not sectioning content; it doesn't
- introduce a new section.
The footer element is not sectioning content.
Headings and sections
-The h1–h6 elements and the hgroup element are
- headings.
Heading content elements have a heading level, which is either null or + an unsigned integer. It is determined as follows for a given heading content element + heading:
-The first element of heading content in an element of sectioning - content represents the heading for that section. Subsequent headings of equal - or higher rank start new (implied) sections, headings of lower rank - start implied subsections that are part of the previous one. In both cases, the element - represents the heading of the implied section.
+-
+
If heading has a parent
hgroupelement, then return null.
- -
+
Switch on heading:
- --
-
blockquote
- body
- details
- dialog
- fieldset
- figure
- td
-
-
+
h2
+ - Return 2. - +
h3
+ - Return 3. -
h4
+ - Return 4. + +
h5
+ - Return 5. + +
h6
+ - Return 6. +
Sectioning content elements are always considered subsections of their nearest - ancestor sectioning root or their nearest ancestor element of sectioning - content, whichever is nearest, regardless of what implied sections other headings may have - created.
+
+
+ Return the number of ancestor sectioning content elements + 1.
+
Certain elements are said to be sectioning roots, including
- blockquote and td elements. These elements can have their own outlines,
- but the sections and headings inside these elements do not contribute to the outlines of their
- ancestors.
A heading content element whose heading level is non-null + represents a heading. The lower a heading's heading level is, the more important the + heading is.
+ +I.e., headings are heading
+ content elements whose parent is not an hgroup element.
The document headings are all headings in a + document, in tree order.
+ +The document headings must be used for generating document outlines, for + example when generating tables of contents. When creating an interactive table of contents, + entries should jump the user to the relevant heading.
-For the following fragment:
-<body>
- <h1>Foo</h1>
- <h2>Bar</h2>
- <blockquote>
- <h3>Bla</h3>
- </blockquote>
- <p>Baz</p>
- <h2>Quux</h2>
- <section>
- <h3>Thud</h3>
- </section>
- <p>Grunt</p>
-</body>...the structure would be:
--
-
-
- Foo (heading of explicit
bodysection, containing the "Grunt" paragraph) --
-
- - Bar (heading starting implied section, containing a block quote and the "Baz" paragraph) - -
- - Quux (heading starting implied section with no content other than the heading itself) - -
-
- Thud (heading of explicit
sectionsection) -
-
-
Notice how the section ends the earlier implicit section so that a later
- paragraph ("Grunt") is back at the top level.
Sections may contain headings of any rank, but authors are strongly encouraged to
- either use only h1 elements, or to use elements of the appropriate rank
- for the section's nesting level.
If a document has a heading, at least a single heading within document headings must have a + heading level of 1.
-Authors are also encouraged to explicitly wrap sections in elements of sectioning - content, instead of relying on the implicit sections generated by having multiple headings - in one element of sectioning content.
+Each heading following another heading lead in document headings must + have a heading level that is less, equal, or 1 greater than lead's + heading level.
+ +Authors are encouraged to avoid having a sectioning content element + section without a heading descendant whose + nearest ancestor sectioning content element is not section. I.e., avoid + having a section without a heading.
For example, the following is correct:
+The following example is non-conforming:
<body>
<h4>Apples</h4>
@@ -16874,14 +16819,10 @@ Space is not the only voidHowever, the same document would be more clearly expressed as:
+It could be written as follows and then it would be conforming:
<body>
<h1>Apples</h1>
@@ -16889,22 +16830,12 @@ Space is not the only voidBoth of the documents above are semantically identical and would produce the same outline in - compliant user agents.
- -This third example is also semantically identical, and might be easier to maintain (e.g. if - sections are often moved around in editing):
+It could also be written as follows, and this might be preferable if the sections move around
+ a lot, as the heading level of h1 elements depends on the number of
+ ancestor sectioning content elements:
<body>
<h1>Apples</h1>
@@ -16912,51 +16843,12 @@ Space is not the only voidThis final example would need explicit style rules to be rendered well in legacy browsers. - Legacy browsers without CSS support would render all the headings as top-level headings.
- -Creating an outline
- -This section defines an algorithm for creating an outline for a sectioning content - element or a sectioning root element. It is defined in terms of a walk over the nodes - of a DOM tree, in tree order, with each node being visited when it is entered and when it - is exited during the walk.
-The outline for a sectioning content element or a sectioning - root element consists of a list of one or more potentially nested sections. The element for which an outline is created - is said to be the outline's owner.
- -A section is a container that corresponds to some nodes in
- the original DOM tree. Each section can have one heading associated with it, and can contain any
- number of further nested sections. The algorithm for the outline also
- associates each node in the DOM tree with a particular section and potentially a heading.
- (The sections in the outline aren't section elements, though some may correspond to
- such elements — they are merely conceptual sections.)
The following markup fragment:
<body>
@@ -16971,418 +16863,27 @@ Space is not the only void...results in the following outline being created for the body node (and thus the
- entire document):
...results in 3 document headings:
-
-
-
-
Section created for
-bodynode.Associated with heading
-<hgroup - id="document-title">...</hgroup>consisting of primary heading<h1>HTML</h1>and secondary heading<h2>Living - Standard — Last Updated 12 August 2016</h2>.Also associated with the paragraph
-<p>Some intro to the - document.</p>(though it likely would not be shown in a rendered view of the - outline).Nested sections:
--
-
-
-
Section implied for first
-h2element.Associated with heading
-<h2>Table of contents</h2>.Also associated with the ordered list
-<ol id=toc>...</ol>- (though it likely would not be shown in a rendered view of the outline).No nested sections.
-
- -
-
Section implied for second
-h2element.Associated with heading
-<h2>First section</h2>.Also associated with the paragraph
-<p>Some intro to the first - section.</p>(though it likely would not be shown in a rendered view of the - outline).No nested sections.
-
-
+ -
-
<hgroup id="document-title">...</hgroup>consisting of<h1>HTML</h1>and<h2>Living Standard — Last Updated 12 August 2016</h2>.
+
+ <h2>Table of contents</h2>.
+
+ <h2>First section</h2>.
The following image shows what a rendered view of the outline might look like.
+A rendered view of the document headings might look like:
The algorithm that must be followed during a walk of a DOM subtree rooted at a sectioning - content element or a sectioning root element to determine that element's - outline is as follows:
- --
-
-
Let current outline target be null. (It holds the element whose - outline is being created.)
-
- Let current section be null. (It holds a pointer to a section, so that elements in the DOM can all be associated with a - section.)
-
- Create a stack to hold elements, which is used to handle nesting. Initialize this stack to - empty.
-
- -
-
-
Walk over the DOM in tree order, starting with the sectioning - content element or sectioning root element at the root of the subtree for - which an outline is to be created, and trigger the first relevant step below for each element as - the walk enters and exits it.
- --
-
-
- When exiting an element, if that element is the element at the top of the stack - -
-
-
-
The element being exited is a heading content element or an - element with a
- -hiddenattribute.Pop that element from the stack.
- -
-
-
- - If the top of the stack is a heading content element or an element with a
-
hiddenattribute
-
- Do nothing.
-
-
- - When entering an element with a
hiddenattribute
-
- -
-
-
Push the element being entered onto the stack. (This causes the algorithm to skip that - element and any descendants of the element.)
- -
-
-
- - When entering a sectioning content element - -
-
-
-
Run these steps:
- --
-
-
-
-
-
If current outline target is not null, then:
- --
-
-
If the current section has no heading, create an implied - heading and let that be the heading for the current section.
-
- Push current outline target onto the stack.
-
-
-
- Let current outline target be the element that is being - entered.
-
- Let current section be a newly created section for the current outline target - element.
-
- Associate current outline target with current - section.
-
- Let there be a new outline for the new current outline - target, initialized with just the new current section as the only - section in the outline.
-
-
-
-
- -
-
-
- When exiting a sectioning content element, if the stack is not empty - -
-
-
-
Run these steps:
- --
-
-
If the current section has no heading, create an implied heading - and let that be the heading for the current section.
-
- Pop the top element from the stack, and let the current outline - target be that element.
-
- Let current section be the last section in the - outline of the current outline target element.
-
- Append the outline of the sectioning content element being - exited to the current section. (This does not change which section is - the last section in the outline.)
-
-
-
-
- - When entering a sectioning root element - -
-
-
-
Run these steps:
- --
-
-
If current outline target is not null, push current outline target onto the stack.
-
- Let current outline target be the element that is being - entered.
-
- Let current outline target's parent section be current section.
-
- Let current section be a newly created section for the current outline target - element.
-
- Let there be a new outline for the new current outline - target, initialized with just the new current section as the only - section in the outline.
-
-
-
-
- - When exiting a sectioning root element, if the stack is not empty - -
-
-
-
Run these steps:
- --
-
-
If the current section has no heading, create an implied heading - and let that be the heading for the current section.
-
- Let current section be current outline - target's parent section.
-
- Pop the top element from the stack, and let the current outline - target be that element.
-
-
-
-
- - When exiting a sectioning content element or a sectioning root - element (when the stack is empty) - -
-
-
-
The current outline target is the element being exited, - and it is the sectioning content element or a sectioning root - element at the root of the subtree for which an outline is being generated.
- -If the current section has no heading, create an implied heading and - let that be the heading for the current section.
- -Skip to the next step in the overall set of steps. (The walk is over.)
- -
-
-
- - When entering a heading content element - -
-
-
-
If the current section has no heading, let the element being entered be - the heading for the current section.
- -If the element being entered is an
- -hgroupelement, that -hgroupas a whole is a multi-level heading for the current - section, with the highest-ranked -h1–h6descendant of thehgroupproviding the - primary heading for the current section, and with other -h1–h6descendants of thehgroupproviding - secondary headings for the current section.Otherwise, if the element being entered has a rank equal to or higher than the - heading of the last section of the outline of the current outline - target, or if the heading of the last section of the outline of the current outline target is an implied heading, then create a new section and append it to the outline of the current outline target element, so that this new section is the new last - section of that outline. Let current section be that new section. Let the - element being entered be the new heading for the current section.
- -Otherwise, run these substeps:
- --
-
-
Let candidate section be current - section.
-
- Heading loop: If the element being entered has a rank lower than - the rank of the heading of the candidate section, then create a new - section, and append it to candidate - section. (This does not change which section is the last section in the outline.) Let - current section be this new section. Let the element being entered be the - new heading for the current section. Abort these substeps.
- -Let new candidate section be the section that contains candidate section in - the outline of current outline target.
-
- Let candidate section be new candidate - section.
-
- Return to the step labeled heading loop.
-
-
Push the element being entered onto the stack. (This causes the algorithm to skip any - descendants of the element.)
- -Recall that
- -h1has the highest rank, andh6- has the lowest rank.
-
-
- - Otherwise - -
Do nothing.
-
-
In addition, whenever the walk exits a node, after doing the steps - above, if the node is not associated with a section yet, - associate the node with the section current - section.
- -
-
- Associate all non-element nodes that are in the subtree for which an outline is being - created with the section with which their parent element is - associated.
-
- Associate all nodes in the subtree with the heading of the section with which they are associated, if any.
-
-
The tree of sections created by the algorithm above, or a proper subset thereof, must be used - when generating document outlines, for example when generating tables of contents.
- -The outline created for the body element of a Document is the
- outline of the entire document.
When creating an interactive table of contents, entries should jump the user to the relevant - sectioning content element, if the section was - created for a real element in the original document, or to the relevant heading - content element, if the section in the tree was - generated for a heading in the above process.
- -Selecting the first section of the document
- therefore always takes the user to the top of the document, regardless of where the first heading
- in the body is to be found.
The outline depth of a heading content element associated with a section section is the number of sections that are ancestors of section in the
- outermost outline that section finds itself in when the outlines of its Document's elements are created, plus 1. The
- outline depth of a heading content element not associated with a section is 1.
User agents should provide default headings for sections that do not have explicit section - headings.
- -Consider the following snippet:
- -<body>
- <nav>
- <p><a href="/">Home</a></p>
- </nav>
- <p>Hello world.</p>
- <aside>
- <p>My cat is cute.</p>
- </aside>
-</body>Although it contains no headings, this snippet has three sections: a document (the
- body) with two subsections (a nav and an aside). A user
- agent could present the outline as follows:
-
-
- Untitled document
-
-
-
- Navigation -
- Sidebar -
-
These default headings ("Untitled document", "Navigation", "Sidebar") are not specified by - this specification, and might vary with the user's language, the page's language, the user's - preferences, the user agent implementer's preferences, etc.
- -The following JavaScript function shows how the tree walk could be implemented. The root argument is the root of the tree to walk (either a sectioning - content element or a sectioning root element), and the enter and exit arguments are callbacks that are called with - the nodes as they are entered and exited.
- -function (root, enter, exit) {
- var node = root;
- start: while (node) {
- enter(node);
- if (node.firstChild) {
- node = node.firstChild;
- continue start;
- }
- while (node) {
- exit(node);
- if (node == root) {
- node = null;
- } else if (node.nextSibling) {
- node = node.nextSibling;
- continue start;
- } else {
- node = node.parentNode;
- }
- }
- }
-}Sample outlines
- - -The following document shows a straight-forward application of the outline - algorithm. First, here is the document, which is a book with very short chapters and - subsections:
+First, here is a document, which is a book with very short chapters and subsections:
<!DOCTYPE HTML>
<html lang=en>
@@ -17405,7 +16906,7 @@ Space is not the only voidThis book would form the following outline:
+Its document headings could be presented as follows:
- The Tax Book @@ -17427,14 +16928,13 @@ Space is not the only void
Notice that the title element does not participate in the outline.
Notice that the title element is not a heading.
Here is a similar document, but this time using section elements to get the same
- effect:
Here is a similar document, but this time using h1 and section
+ elements to get the same effect:
<!DOCTYPE HTML>
<html lang=en>
@@ -17473,7 +16973,7 @@ Space is not the only voidThis book would form the same outline:
+Its document headings could be presented identically:
- The Tax Book @@ -17494,11 +16994,9 @@ Space is not the only void
A document can contain multiple top-level headings:
<!DOCTYPE HTML>
@@ -17510,26 +17008,11 @@ Space is not the only voidThis would form the following simple outline consisting of three top-level sections:
- --
-
- Apples -
- Bananas -
- Carambola -
Effectively, the body element is split into three.
Mixing both the h1–h6 model and the
- section/h1 model can lead to some unintuitive results.
Consider for example the following, which is just the previous example but with the contents
- of the (implied) body wrapped in a section:
The following example is non-conforming as it has no heading whose heading level is 1:
<!DOCTYPE HTML>
<html lang=en>
@@ -17542,32 +17025,11 @@ Space is not the only voidThe resulting outline would be:
- --
-
- (untitled page)
-
-
-
- Apples -
- Bananas -
- Carambola -
This result is described as unintuitive because it results in three subsections even
- though there's only one section element. Effectively, the section is
- split into three, just like the implied body element in the previous example.
(In this example, "(untitled page)" is the implied heading for the body
- element, since it has no explicit heading.)
Headings never rise above other sections. Thus, in the following example, the first
- h1 does not actually describe the page header; it describes the header for the
- second half of the page:
The following example is non-conforming as the first heading's heading level is not 1:
<!DOCTYPE HTML>
<html lang=en>
@@ -17578,24 +17040,11 @@ Space is not the only voidThe resulting outline would be:
- --
-
- (untitled page)
-
-
-
- A plea from our caretakers -
- Feathers -
Thus, when an article element starts with a nav block and only later
- has its heading, the result is that the nav block is not part of the same section as
- the rest of the article in the outline. For instance, take this document:
header elements do not influence the document headings of a
+ document:
<!DOCTYPE HTML>
<html lang="en">
@@ -17616,26 +17065,17 @@ Space is not the only voidThe resulting outline would be:
+The document's document headings could be presented as follows:
- Ray's blog
-
-
- Untitled article
-
-
-
- Untitled navigation section -
- We're adopting a child!
- Untitled article
-
Also worthy of note in this example is that the header element has no effect
- whatsoever on the document outline.
The hgroup element can be used for subheadings. For example:
<!DOCTYPE HTML>
@@ -17651,12 +17091,14 @@ Space is not the only voidThe resulting outline would be:
+The document's document headings could be presented as follows:
- The morning 06:00 to 12:00
- The afternoon 12:00 to 18:00
-
-
- Additional Commentary Because not all this is necessarily true Ok it's almost certainly not true +
- Additional Commentary Because not all this is necessarily true Ok it's + almost certainly not true
- The evening 18:00 to 00:00
- The night 00:00 to 06:00 @@ -17690,13 +17133,14 @@ Space is not the only void
- The morning — 06:00 to 12:00
- The afternoon — 12:00 to 18:00
-
-
- Additional Commentary — Because not all this is necessarily true — Ok it's almost certainly not true +
- Additional Commentary — Because not all this is necessarily true — Ok it's + almost certainly not true
- The evening — 18:00 to 00:00
- The night — 00:00 to 06:00
But so would the following:
+And so would the following:
- The morning @@ -17707,62 +17151,6 @@ Space is not the only void
- The evening
- The night
The following would also be valid, though maybe less practical in most contexts:
- --
-
-
The morning -
06:00 to 12:00 -
-
The afternoon -
12:00 to 18:00 -
-
-
-
Additional Commentary -
Because not all this is necessarily true -
Ok it's almost certainly not true -
-
-
The evening -
18:00 to 00:00 -
-
The night -
00:00 to 06:00 -
Exposing outlines to users
- -User agents are encouraged to expose page outlines to users to aid in navigation. This is - especially true for non-visual media, e.g. screen readers.
- -However, to mitigate the difficulties that arise from authors misusing sectioning - content, user agents are also encouraged to offer a mode that navigates the page using - heading content alone.
- -For instance, a user agent could map the arrow keys as follows:
- --
-
-
- Shift+← Left -
- Go to previous section, including subsections of previous sections - -
- Shift+→ Right -
- Go to next section, including subsections of the current section - -
- Shift+↑ Up -
- Go to parent section of the current section - -
- Shift+↓ Down -
- Go to next section, skipping subsections of the current section - -
Plus in addition, the user agent could map the j and - k keys to navigating to the previous or next element of heading - content, regardless of the section's outline depth and ignoring sections with no - headings.
-h1–h6
- <h1>The Guide To Music On The Playa</h1>
<h2>The Main Stage</h2>
@@ -17849,7 +17237,7 @@ Space is not the only voidhgroup
- <hgroup>
<h1>Burning Music</h1>
@@ -18162,8 +17550,6 @@ of Gralmond's winters.</p>The hr element does not affect the document's
- outline.
The pre element
@@ -18284,7 +17670,6 @@ a friend lost to the
- Categories:
- Flow content. -
- Sectioning root.
- Palpable content.
- Contexts in which this element can be used:
- Where flow content is expected. @@ -19290,7 +18675,6 @@ first matching case):</p>
- Categories:
- Flow content. -
- Sectioning root.
- Palpable content.
- Contexts in which this element can be used:
- Where flow content is expected. @@ -40937,7 +40321,7 @@ interface HTMLTableRowElement : HTMLElement {
- Categories: -
- Sectioning root. +
- None.
- Contexts in which this element can be used:
- As a child of a
trelement. - Content model: @@ -41038,7 +40422,6 @@ interface HTMLTableCellElement : HTMLElement {
- Content model:
- Flow content, but with no
header,footer, sectioning content, or heading content descendants.
-
- Content attributes:
- Global attributes
colspan
@@ -52491,7 +51874,6 @@ out of 233 257 824 bytes available</meter></p>
- Categories:
- Flow content. -
- Sectioning root.
- Listed and autocapitalize-inheriting form-associated element.
- Palpable content.
- Contexts in which this element can be used: @@ -57149,7 +56531,6 @@ dictionary FormDataEventInit : EventInit {
- Categories:
- Flow content. -
- Sectioning root.
- Interactive content.
- Palpable content.
- Contexts in which this element can be used: @@ -57648,7 +57029,6 @@ interface HTMLDetailsElement : HTMLElement {
- Categories:
- Flow content. -
- Sectioning root.
- Contexts in which this element can be used:
- Where flow content is expected.
- Content model: @@ -68840,6 +68220,24 @@ contradict people? these selectors match HTML elements.
:heading
+ :heading()
+
+ -
+
The
+ +:headingpseudo-class must match any + element that is a heading.The
+:heading()functional + pseudo-class accepts a level. + Level must be a positive + <integer>. The:heading()+ functional pseudo-class must match any element that is a heading whose heading level is level.
+
:defined
;
-
+
video (if the controls attribute is present)
- blockquote;
- body;
- details;
- dialog;
- fieldset;
- figure;
- td
-