a
elementhref
target
ping
rel
media
hreflang
type
[Stringifies=href] interface HTMLAnchorElement : HTMLElement { attribute DOMString href; attribute DOMString target; attribute DOMString ping; attribute DOMString rel; readonly attribute DOMTokenList relList; attribute DOMString media; attribute DOMString hreflang; attribute DOMString type; };
The Command
interface must also be implemented by
this element.
If the a
element has an href
attribute, then it
represents a hyperlink (a hypertext
anchor).
If the a
element has no href
attribute, then the element
represents a placeholder for where a link might
otherwise have been placed, if it had been relevant.
The target
, ping
, rel
, media
, hreflang
, and type
attributes must be omitted
if the href
attribute is
not present.
If a site uses a consistent navigation tool bar on every page,
then the link that would normally link to the page itself could be
marked up using an a
element:
<nav> <ul> <li> <a href="/">Home</a> </li> <li> <a href="/news">News</a> </li> <li> <a>Examples</a> </li> <li> <a href="/legal">Legal</a> </li> </ul> </nav>
Interactive user agents should allow users to follow hyperlinks created using
the a
element. The href
, target
and ping
attributes decide how the
link is followed. The rel
,
media
, hreflang
, and type
attributes may be used to
indicate to the user the likely nature of the target resource before
the user follows the link.
The activation behavior of a
elements
that represent hyperlinks is to run the following
steps:
If the DOMActivate
event in question is not trusted (i.e. a click()
method call was the reason for the
event being dispatched), and the a
element's target
attribute is ... then raise an
INVALID_ACCESS_ERR
exception and abort these
steps.
If the target of the click
event is an img
element with an ismap
attribute specified, then
server-side image map processing must be performed, as follows:
DOMActivate
event was dispatched as the result of a real
pointing-device-triggered click
event on the img
element, then let x be the distance in CSS pixels from the left edge
of the image's left border, if it has one, or the left edge of
the image otherwise, to the location of the click, and let y be the distance in CSS pixels from the top edge
of the image's top border, if it has one, or the top edge of the
image otherwise, to the location of the click. Otherwise, let
x and y be zero.Finally, the user agent must follow the hyperlink defined by the
a
element. If the steps above defined a hyperlink
suffix, then take that into account when following the
hyperlink.
The DOM attributes href
, ping
, target
, rel
, media
, hreflang
, and type
, must
reflect the respective content attributes of the same
name.
The DOM attribute relList
must
reflect the rel
content attribute.
The a
element may be wrapped around entire
paragraphs, lists, tables, and so forth, even entire sections, so
long as there is no interactive content within (e.g. buttons or
other links). This example shows how this can be used to make an
entire advertising block into a link:
<aside class="advertising"> <h1>Advertising</h1> <a href="http://ad.example.com/?adid=1929&pubid=1422"> <section> <h1>Mellblomatic 9000!</h1> <p>Turn all your widgets into mellbloms!</p> <p>Only $9.99 plus shipping and handling.</p> </section> </a> <a href="http://ad.example.com/?adid=375&pubid=1422"> <section> <h1>The Mellblom Browser</h1> <p>Web browsing at the speed of light.</p> <p>No other browser goes faster!</p> </section> </a> </aside>
q
elementcite
q
element uses the HTMLQuoteElement
interface.
The q
element represents some phrasing content quoted from another
source.
Quotation punctuation (such as quotation marks) must not appear
immediately before, after, or inside q
elements; they
will be inserted into the rendering by the user agent.
Content inside a q
element must be quoted from
another source, whose address, if it has one, should be cited in the
cite
attribute. The
source may be fictional, as when quoting characters in a novel or
screenplay.
If the cite
attribute is
present, it must be a valid URL. To obtain the
corresponding citation link, the value of the attribute must be
resolved relative to the
element. User agents should allow users to follow such citation
links.
The q
element must not be used in place of quotation
marks that do not represent quotes; for example, it is inappropriate
to use the q
element for marking up sarcastic
statements.
The use of q
elements to mark up quotations is
entirely optional; using explicit quotation punctuation without
q
elements is just as correct.
Here is a simple example of the use of the q
element:
<p>The man said <q>Things that are impossible just take longer</q>. I disagreed with him.</p>
Here is an example with both an explicit citation link in the
q
element, and an explicit citation outside:
<p>The W3C page <cite>About W3C</cite> says the W3C's mission is <q cite="http://www.w3.org/Consortium/">To lead the World Wide Web to its full potential by developing protocols and guidelines that ensure long-term growth for the Web</q>. I disagree with this mission.</p>
In the following example, the quotation itself contains a quotation:
<p>In <cite>Example One</cite>, he writes <q>The man said <q>Things that are impossible just take longer</q>. I disagreed with him</q>. Well, I disagree even more!</p>
In the following example, quotation marks are used instead of
the q
element:
<p>His best argument was ❝I disagree❞, which I thought was laughable.</p>
In the following example, there is no quote — the
quotation marks are used to name a word. Use of the q
element in this case would be inappropriate.
<p>The word "ineffable" could have been used to describe the disaster resulting from the campaign's mismanagement.</p>
cite
elementHTMLElement
.The cite
element represents the title
of a work (e.g.
a book,
a paper,
an essay,
a poem,
a score,
a song,
a script,
a film,
a TV show,
a game,
a sculpture,
a painting,
a theatre production,
a play,
an opera,
a musical,
an exhibition,
etc). This can be a work that is being quoted or
referenced in detail (i.e. a citation), or it can just be a work
that is mentioned in passing.
A person's name is not the title of a work — even if people
call that person a piece of work — and the element must
therefore not be used to mark up people's names. (In some cases, the
b
element might be appropriate for names; e.g. in a
gossip article where the names of famous people are keywords
rendered with a different style to draw attention to them. In other
cases, if an element is really needed, the
span
element can be used.)
A ship is similarly not a work, and the element must not be used
to mark up ship names (the i
element can be used for
that purpose).
This next example shows a typical use of the cite
element:
<p>My favourite book is <cite>The Reality Dysfunction</cite> by Peter F. Hamilton. My favourite comic is <cite>Pearls Before Swine</cite> by Stephan Pastis. My favourite track is <cite>Jive Samba</cite> by the Cannonball Adderley Sextet.</p>
This is correct usage:
<p>According to the Wikipedia article <cite>HTML</cite>, as it stood in mid-February 2008, leaving attribute values unquoted is unsafe. This is obviously an over-simplification.</p>
The following, however, is incorrect usage, as the
cite
element here is containing far more than the
title of the work:
<!-- do not copy this example, it is an example of bad usage! --> <p>According to <cite>the Wikipedia article on HTML</cite>, as it stood in mid-February 2008, leaving attribute values unquoted is unsafe. This is obviously an over-simplification.</p>
The cite
element is obviously a key part of any
citation in a bibliography, but it is only used to mark the
title:
<p><cite>Universal Declaration of Human Rights</cite>, United Nations, December 1948. Adopted by General Assembly resolution 217 A (III).</p>
A citation is not a quote (for
which the q
element is appropriate).
This is incorrect usage, because cite
is not for
quotes:
<p><cite>This is wrong!</cite>, said Ian.</p>
This is also incorrect usage, because a person is not a work:
<p><q>This is still wrong!</q>, said <cite>Ian</cite>.</p>
The correct usage does not use a cite
element:
<p><q>This is correct</q>, said Ian.</p>
As mentioned above, the b
element might be relevant
for marking names as being keywords in certain kinds of
documents:
<p>And then <b>Ian</b> said <q>this might be right, in a gossip column, maybe!</q>.</p>
em
elementHTMLElement
.The em
element represents stress
emphasis of its contents.
The level of emphasis that a particular piece of content has is
given by its number of ancestor em
elements.
The placement of emphasis changes the meaning of the sentence. The element thus forms an integral part of the content. The precise way in which emphasis is used in this way depends on the language.
These examples show how changing the emphasis changes the meaning. First, a general statement of fact, with no emphasis:
<p>Cats are cute animals.</p>
By emphasizing the first word, the statement implies that the kind of animal under discussion is in question (maybe someone is asserting that dogs are cute):
<p><em>Cats</em> are cute animals.</p>
Moving the emphasis to the verb, one highlights that the truth of the entire sentence is in question (maybe someone is saying cats are not cute):
<p>Cats <em>are</em> cute animals.</p>
By moving it to the adjective, the exact nature of the cats is reasserted (maybe someone suggested cats were mean animals):
<p>Cats are <em>cute</em> animals.</p>
Similarly, if someone asserted that cats were vegetables, someone correcting this might emphasize the last word:
<p>Cats are cute <em>animals</em>.</p>
By emphasizing the entire sentence, it becomes clear that the speaker is fighting hard to get the point across. This kind of emphasis also typically affects the punctuation, hence the exclamation mark here.
<p><em>Cats are cute animals!</em></p>
Anger mixed with emphasizing the cuteness could lead to markup such as:
<p><em>Cats are <em>cute</em> animals!</em></p>
strong
elementHTMLElement
.The strong
element represents strong
importance for its contents.
The relative level of importance of a piece of content is given
by its number of ancestor strong
elements; each
strong
element increases the importance of its
contents.
Changing the importance of a piece of text with the
strong
element does not change the meaning of the
sentence.
Here is an example of a warning notice in a game, with the various parts marked up according to how important they are:
<p><strong>Warning.</strong> This dungeon is dangerous. <strong>Avoid the ducks.</strong> Take any gold you find. <strong><strong>Do not take any of the diamonds</strong>, they are explosive and <strong>will destroy anything within ten meters.</strong></strong> You have been warned.</p>
small
elementHTMLElement
.The small
element represents small
print (part of a document often describing disclaimers, caveats, or
legal restrictions, such as copyrights or other disadvantages), or
other side comments.
The small
element does not
"de-emphasize" or lower the importance of text emphasised by the
em
element or marked as important with the
strong
element.
In this example the footer contains contact information and a copyright.
<footer> <address> For more details, contact <a href="mailto:js@example.com">John Smith</a>. </address> <p><small>© copyright 2038 Example Corp.</small></p> </footer>
In this second example, the small
element is used
for a side comment in an article.
<p>Example Corp today announced record profits for the second quarter <small>(Full Disclosure: Foo News is a subsidiary of Example Corp)</small>, leading to speculation about a third quarter merger with Demo Group.</p>
This is distinct from a sidebar, which might be multiple paragraphs long and is removed from the main flow of text. In the following example, we see a sidebar from the same article. This sidebar also has small print, indicating the source of the information in the sidebar.
<aside> <h1>Example Corp</h1> <p>This company mostly creates small software and Web sites.</p> <p>The Example Corp company mission is "To provide entertainment and news on a sample basis".</p> <p><small>Information obtained from <a href="http://example.com/about.html">example.com</a> home page.</small></p> </aside>
In this last example, the small
element is marked
as being important small print.
<p><strong><small>Continued use of this service will result in a kiss.</small></strong></p>
mark
elementHTMLElement
.The mark
element represents a run of
text in one document marked or highlighted for reference purposes,
due to its relevance in another context. When used in a quotation or
other block of text referred to from the prose, it indicates a
highlight that was not originally present but which has been added
to bring the reader's attention to a part of the text that might not
have been considered important by the original author when the block
was originally written, but which is now under previously unexpected
scrutiny. When used in the main prose of a document, it indicates a
part of the document that has been highlighted due to its likely
relevance to the user's current activity.
This example shows how the mark
example can be used
to bring attention to a particular part of a quotation:
<p lang="en-US">Consider the following quote:</p> <blockquote lang="en-GB"> <p>Look around and you will find, no-one's really <mark>colour</mark> blind.</p> </blockquote> <p lang="en-US">As we can tell from the <em>spelling</em> of the word, the person writing this quote is clearly not American.</p>
Another example of the mark
element is highlighting
parts of a document that are matching some search string. If
someone looked at a document, and the server knew that the user was
searching for the word "kitten", then the server might return the
document with one paragraph modified as follows:
<p>I also have some <mark>kitten</mark>s who are visiting me these days. They're really cute. I think they like my garden! Maybe I should adopt a <mark>kitten</mark>.</p>
In the following snippet, a paragraph of text refers to a specific part of a code fragment.
<p>The highlighted part below is where the error lies:</p> <pre><code>var i: Integer; begin i := <mark>1.1</mark>; end.</code></pre>
This is another example showing the use of mark
to
highlight a part of quoted text that was originally not
emphasised. In this example, common typographic conventions have
led the author to explicitly style mark
elements in
quotes to render in italics.
<article> <style> blockquote mark, q mark { font: inherit; font-style: italic; text-decoration: none; background: transparent; color: inherit; } .bubble em { font: inherit; font-size: larger; text-decoration: underline; } </style> <h1>She knew</h1> <p>Did you notice the subtle joke in the joke on panel 4?</p> <blockquote> <p class="bubble">I didn't <em>want</em> to believe. <mark>Of course on some level I realized it was a known-plaintext attack.</mark> But I couldn't admit it until I saw for myself.</p> </blockquote> <p>(Emphasis mine.) I thought that was great. It's so pedantic, yet it explains everything neatly.</p> </article>
Note, incidentally, the distinction between the em
element in this example, which is part of the original text being
quoted, and the mark
element, which is highlighting a
part for comment.
The following example shows the difference between denoting the
importance of a span of text (strong
) as
opposed to denoting the relevance of a span of text
(mark
). It is an extract from a textbook, where the
extract has had the parts relevant to the exam highlighted. The
safety warnings, important though they may be, are apparently not
relevant to the exam.
<h3>Wormhole Physics Introduction</h3> <p><mark>A wormhole in normal conditions can be held open for a maximum of just under 39 minutes.</mark> Conditions that can increase the time include a powerful energy source coupled to one or both of the gates connecting the wormhole, and a large gravity well (such as a black hole).</p> <p><mark>Momentum is preserved across the wormhole. Electromagnetic radiation can travel in both directions through a wormhole, but matter cannot.</mark></p> <p>When a wormhole is created, a vortex normally forms. <strong>Warning: The vortex caused by the wormhole opening will annihilate anything in its path.</strong> Vortexes can be avoided when using sufficiently advanced dialing technology.</p> <p><mark>An obstruction in a gate will prevent it from accepting a wormhole connection.</mark></p>
dfn
elementdfn
elements.title
attribute has special semantics on this element.HTMLElement
.The dfn
element represents the defining
instance of a term. The paragraph,
description list group, or section that is the nearest
ancestor of the dfn
element must also contain the
definition(s) for the term given
by the dfn
element.
Defining term: If the dfn
element has a
title
attribute, then
the exact value of that attribute is the term being defined.
Otherwise, if it contains exactly one element child node and no
child text nodes, and that child
element is an abbr
element with a title
attribute, then the exact value
of that attribute is the term being defined. Otherwise, it
is the exact textContent
of the dfn
element that gives the term being defined.
If the title
attribute of the
dfn
element is present, then it must contain only the
term being defined.
The title
attribute
of ancestor elements does not affect dfn
elements.
An a
element that links to a dfn
element represents an instance of the term defined by the
dfn
element.
In the following fragment, the term "GDO" is first defined in the first paragraph, then used in the second.
<p>The <dfn><abbr title="Garage Door Opener">GDO</abbr></dfn> is a device that allows off-world teams to open the iris.</p> <!-- ... later in the document: --> <p>Teal'c activated his <abbr title="Garage Door Opener">GDO</abbr> and so Hammond ordered the iris to be opened.</p>
With the addition of an a
element, the reference
can be made explicit:
<p>The <dfn id=gdo><abbr title="Garage Door Opener">GDO</abbr></dfn> is a device that allows off-world teams to open the iris.</p> <!-- ... later in the document: --> <p>Teal'c activated his <a href=#gdo><abbr title="Garage Door Opener">GDO</abbr></a> and so Hammond ordered the iris to be opened.</p>
abbr
elementtitle
attribute has special semantics on this element.HTMLElement
.The abbr
element represents an
abbreviation or acronym, optionally with its expansion. The title
attribute may be
used to provide an expansion of the abbreviation. The attribute, if
specified, must contain an expansion of the abbreviation, and
nothing else.
The paragraph below contains an abbreviation marked up with the
abbr
element. This paragraph defines the term "Web Hypertext Application Technology
Working Group".
<p>The <dfn id=whatwg><abbr title="Web Hypertext Application Technology Working Group">WHATWG</abbr></dfn> is a loose unofficial collaboration of Web browser manufacturers and interested parties who wish to develop new technologies designed to allow authors to write and deploy Applications over the World Wide Web.</p>
An alternative way to write this would be:
<p>The <dfn id=whatwg>Web Hypertext Application Technology Working Group</dfn> (<abbr title="Web Hypertext Application Technology Working Group">WHATWG</abbr>) is a loose unofficial collaboration of Web browser manufacturers and interested parties who wish to develop new technologies designed to allow authors to write and deploy Applications over the World Wide Web.</p>
This paragraph has two abbreviations. Notice how only one is
defined; the other, with no expansion associated with it, does not
use the abbr
element.
<p>The <abbr title="Web Hypertext Application Technology Working Group">WHATWG</abbr> started working on HTML5 in 2004.</p>
This paragraph links an abbreviation to its definition.
<p>The <a href="#whatwg"><abbr title="Web Hypertext Application Technology Working Group">WHATWG</abbr></a> community does not have much representation from Asia.</p>
This paragraph marks up an abbreviation without giving an expansion, possibly as a hook to apply styles for abbreviations (e.g. smallcaps).
<p>Philip` and Dashiva both denied that they were going to get the issue counts from past revisions of the specification to backfill the <abbr>WHATWG</abbr> issue graph.</p>
If an abbreviation is pluralized, the expansion's grammatical number (plural vs singular) must match the grammatical number of the contents of the element.
Here the plural is outside the element, so the expansion is in the singular:
<p>Two <abbr title="Working Group">WG</abbr>s worked on this specification: the <abbr>WHATWG</abbr> and the <abbr>HTMLWG</abbr>.</p>
Here the plural is inside the element, so the expansion is in the plural:
<p>Two <abbr title="Working Groups">WGs</abbr> worked on this specification: the <abbr>WHATWG</abbr> and the <abbr>HTMLWG</abbr>.</p>
Abbreviations do not have to be marked up using this element. It is expected to be useful in the following cases:
abbr
element with a title
attribute is an alternative to
including the expansion inline (e.g. in parentheses).abbr
element with a title
attribute or include the expansion
inline in the text the first time the abbreviation is used.abbr
element
can be used without a title
attribute.Providing an expansion in a title
attribute once will not necessarily
cause other abbr
elements in the same document with the
same contents but without a title
attribute to behave as if they had the same expansion. Every
abbr
element is independent.
time
elementdatetime
interface HTMLTimeElement : HTMLElement { attribute DOMString dateTime; readonly attribute DOMTimeStamp date; readonly attribute DOMTimeStamp time; readonly attribute DOMTimeStamp timezone; };
The time
element represents a precise
date and/or a time in the proleptic Gregorian calendar. [GREGORIAN]
The datetime
attribute, if present, must contain a valid date or time
string that identifies the date or time being specified.
If the datetime
attribute
is not present, then the date or time must be specified in the
content of the element, such that the element's
textContent
is a valid date or time string in
content.
The dateTime
DOM
attribute must reflect the datetime
content attribute.
User agents, to obtain the date, time, and timezone represented by a
time
element, must follow these steps:
datetime
attribute is present, then use the rules to parse a date or
time string with the flag in attribute from the value
of that attribute, and let the result be result.textContent
, and let the result be result.The date
DOM
attribute must return null if the date is unknown, and otherwise must
return the time corresponding to midnight UTC (i.e. the first
second) of the given date.
The time
DOM attribute
must return null if the time is
unknown, and otherwise must return the time corresponding to the
given time of 1970-01-01, with
the timezone UTC.
The timezone
DOM
attribute must return null if the timezone is unknown, and otherwise
must return the time corresponding to 1970-01-01 00:00 UTC in the
given timezone, with the
timezone set to UTC (i.e. the time corresponding to 1970-01-01 at
00:00 UTC plus the offset corresponding to the timezone).
In the following snippet:
<p>Our first date was <time datetime="2006-09-23">a Saturday</time>.</p>
...the time
element's date
attribute would have the value
1,158,969,600,000ms, and the time
and timezone
attributes would
return null.
In the following snippet:
<p>We stopped talking at <time datetime="2006-09-24T05:00-07:00">5am the next morning</time>.</p>
...the time
element's date
attribute would have the value
1,159,056,000,000ms, the time
attribute would have the value 18,000,000ms, and the timezone
attribute would return
−25,200,000ms. To obtain the actual time, the three attributes can
be added together, obtaining 1,159,048,800,000, which is the
specified date and time in UTC.
Finally, in the following snippet:
<p>Many people get up at <time>08:00</time>.</p>
...the time
element's date
attribute would have the value null,
the time
attribute would have the
value 28,800,000ms, and the timezone
attribute would return
null.
The time
element is not intended for
encoding times for which a precise date or time cannot be
established. For example, it would be inappropriate for encoding
times like "one millisecond after the big bang", "the early part of
the Jurassic period", or "a winter around 250 BCE".
progress
elementvalue
max
interface HTMLProgressElement : HTMLElement { attribute float value; attribute float max; readonly attribute float position; };
The progress
element represents the
completion progress of a task. The progress is either indeterminate,
indicating that progress is being made but that it is not clear how
much more work remains to be done before the task is complete
(e.g. because the task is waiting for a remote host to respond), or
the progress is a number in the range zero to a maximum, giving the
fraction of work that has so far been completed.
There are two attributes that determine the current task completion represented by the element.
The value
attribute specifies how much of the task has been completed, and the
max
attribute
specifies how much work the task requires in total. The units are
arbitrary and not specified.
Instead of using the attributes, authors are recommended to include the current value and the maximum value inline as text inside the element.
Here is a snippet of a Web application that shows the progress of some automated task:
<section> <h2>Task Progress</h2> <p>Progress: <progress><span id="p">0</span>%</progress></p> <script> var progressBar = document.getElementById('p'); function updateProgress(newValue) { progressBar.textContent = newValue; } </script> </section>
(The updateProgress()
method in this example would
be called by some other code on the page to update the actual
progress bar as the task progressed.)
Author requirements: The max
and value
attributes, when present,
must have values that are valid floating point numbers. The max
attribute, if present, must
have a value greater than zero. The value
attribute, if present, must
have a value equal to or greater than zero, and less than or equal
to the value of the max
attribute, if present, or 1, otherwise.
The progress
element is the wrong
element to use for something that is just a gauge, as opposed to
task progress. For instance, indicating disk space usage using
progress
would be inappropriate. Instead, the
meter
element is available for such use cases.
User agent requirements: User agents must parse
the max
and value
attributes' values
according to the rules for parsing floating point number
values.
If the value
attribute
is omitted, then user agents must also parse the
textContent
of the progress
element in
question using the steps for finding one or two numbers of a
ratio in a string. These steps will return nothing, one
number, one number with a denominator punctuation character, or two
numbers.
Using the results of this processing, user agents must determine whether the progress bar is an indeterminate progress bar, or whether it is a determinate progress bar, and in the latter case, what its current and maximum values are, all as follows:
max
attribute is
omitted, and the value
is
omitted, and the results of parsing the textContent
was nothing, then the progress bar is an indeterminate progress
bar. Abort these steps.max
attribute is
included, then, if a value could be parsed out of it, then the
maximum value is that value.max
attribute is absent but the value
attribute is present, or,
if the max
attribute is
present but no value could be parsed from it, then the maximum is
1.textContent
contained one number with an associated
denominator punctuation character, then the maximum value is the
value associated with that denominator punctuation
character; otherwise, if the textContent
contained two numbers, the maximum value is the higher of the two
values; otherwise, the maximum value is 1.value
attribute
is present on the element and a value could be parsed out of it,
that value is the current value of the progress bar. Otherwise, if
the attribute is present but no value could be parsed from it, the
current value is zero.value
attribute is absent and the max
attribute is present, then, if
the textContent
was parsed and found to contain just
one number, with no associated denominator punctuation character,
then the current value is that number. Otherwise, if the value
attribute is absent and
the max
attribute is present
then the current value is zero.textContent
of the element.UA requirements for showing the progress bar:
When representing a progress
element to the user, the
UA should indicate whether it is a determinate or indeterminate
progress bar, and in the former case, should indicate the relative
position of the current value relative to the maximum value.
The max
and value
DOM attributes
must reflect the respective content attributes of the
same name. When the relevant content attributes are absent, the DOM
attributes must return zero. The value parsed from the
textContent
never affects the DOM values.
Would be cool to have the value
DOM attribute update the
textContent
in-line...
If the progress bar is an indeterminate progress bar, then the
position
DOM
attribute must return −1. Otherwise, it must return the result of
dividing the current value by the maximum value.
meter
elementvalue
min
low
high
max
optimum
interface HTMLMeterElement : HTMLElement { attribute float value; attribute float min; attribute float max; attribute float low; attribute float high; attribute float optimum; };
The meter
element represents a scalar
measurement within a known range, or a fractional value; for example
disk usage, the relevance of a query result, or the fraction of a
voting population to have selected a particular candidate.
This is also known as a gauge.
The meter
element should not be used to
indicate progress (as in a progress bar). For that role, HTML
provides a separate progress
element.
The meter
element also does not
represent a scalar value of arbitrary range — for example, it
would be wrong to use this to report a weight, or height, unless
there is a known maximum value.
There are six attributes that determine the semantics of the gauge represented by the element.
The min
attribute
specifies the lower bound of the range, and the max
attribute specifies
the upper bound. The value
attribute
specifies the value to have the gauge indicate as the "measured"
value.
The other three attributes can be used to segment the gauge's
range into "low", "medium", and "high" parts, and to indicate which
part of the gauge is the "optimum" part. The low
attribute specifies
the range that is considered to be the "low" part, and the high
attribute specifies
the range that is considered to be the "high" part. The optimum
attribute
gives the position that is "optimum"; if that is higher than the
"high" value then this indicates that the higher the value, the
better; if it's lower than the "low" mark then it indicates that
lower values are better, and naturally if it is in between then it
indicates that neither high nor low values are good.
Authoring requirements: The recommended way of giving the value is to include it as contents of the element, either as two numbers (the higher number represents the maximum, the other number the current value, and the minimum is assumed to be zero), or as a percentage or similar (using one of the characters such as "%"), or as a fraction. However, it is also possible to use the attributes to specify these values.
One of the following conditions, along with all the requirements that are listed with that condition, must be met:
value
, min
, and max
attributes are all omittedIf specified, the low
,
high
, and optimum
attributes must have
values greater than or equal to zero and less than or equal to the
bigger of the two numbers in the contents of the element.
If both the low
and high
attributes are specified, then
the low
attribute's value must
be less than or equal to the value of the high
attribute.
value
, min
, and max
attributes are all omittedIf specified, the low
,
high
, and optimum
attributes must have
values greater than or equal to zero and less than or equal to the
value associated with the denominator punctuation
character.
If both the low
and high
attributes are specified, then
the low
attribute's value must
be less than or equal to the value of the high
attribute.
value
attribute is
omittedvalue
attribute is
specifiedIf the min
attribute
attribute is specified, then the minimum is
that attribue's value; otherwise, it is 0.
If the max
attribute
attribute is specified, then the maximum is
that attribue's value; otherwise, it is 1.
If there is exactly one number in the contents of the element,
then value is that number; otherwise, value is the value of the value
attribute.
The following inequalities must hold, as applicable:
low
≤ maximum (if low
is specified)high
≤ maximum (if high
is specified)optimum
≤ maximum (if optimum
is specified)If both the low
and high
attributes are specified, then
the low
attribute's value must
be less than or equal to the value of the high
attribute.
For the purposes of these requirements, a number is a sequence of characters in the range U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9), optionally including with a single U+002E FULL STOP character (.), and separated from other numbers by at least one character that isn't any of those; interpreted as a base ten number.
The value
, min
, low
, high
, max
, and optimum
attributes, when present,
must have values that are valid floating point numbers.
If no minimum or maximum is specified, then the range is assumed to be 0..1, and the value thus has to be within that range.
The following examples all represent a measurement of three quarters (of the maximum of whatever is being measured):
<meter>75%</meter> <meter>750‰</meter> <meter>3/4</meter> <meter>6 blocks used (out of 8 total)</meter> <meter>max: 100; current: 75</meter> <meter><object data="graph75.png">0.75</object></meter> <meter min="0" max="100" value="75"></meter>
The following example is incorrect use of the element, because it doesn't give a range (and since the default maximum is 1, both of the gauges would end up looking maxed out):
<p>The grapefruit pie had a radius of <meter>12cm</meter> and a height of <meter>2cm</meter>.</p> <!-- BAD! -->
Instead, one would either not include the meter element, or use the meter element with a defined range to give the dimensions in context compared to other pies:
<p>The grapefruit pie had a radius of 12cm and a height of 2cm.</p> <dl> <dt>Radius: <dd> <meter min=0 max=20 value=12>12cm</meter> <dt>Height: <dd> <meter min=0 max=10 value=2>2cm</meter> </dl>
There is no explicit way to specify units in the
meter
element, but the units may be specified in the
title
attribute in free-form text.
The example above could be extended to mention the units:
<dl> <dt>Radius: <dd> <meter min=0 max=20 value=12 title="centimeters">12cm</meter> <dt>Height: <dd> <meter min=0 max=10 value=2 title="centimeters">2cm</meter> </dl>
User agent requirements: User agents must parse
the min
, max
, value
, low
, high
, and optimum
attributes using the
rules for parsing floating point number values.
If the value
attribute has
been omitted, the user agent must also process the
textContent
of the element according to the steps
for finding one or two numbers of a ratio in a string. These
steps will return nothing, one number, one number with a denominator
punctuation character, or two numbers.
User agents must then use all these numbers to obtain values for six points on the gauge, as follows. (The order in which these are evaluated is important, as some of the values refer to earlier ones.)
If the min
attribute is
specified and a value could be parsed out of it, then the minimum
value is that value. Otherwise, the minimum value is zero.
If the max
attribute is
specified and a value could be parsed out of it, the maximum
value is that value.
Otherwise, if the max
attribute is specified but no value could be parsed out of it, or
if it was not specified, but either or both of the min
or value
attributes were
specified, then the maximum value is 1.
Otherwise, none of the max
,
min
, and value
attributes were
specified. If the result of processing the
textContent
of the element was either nothing or just
one number with no denominator punctuation character, then the
maximum value is 1; if the result was one number but it had an
associated denominator punctuation character, then the maximum
value is the value associated with that denominator
punctuation character; and finally, if there were two
numbers parsed out of the textContent
, then the
maximum is the higher of those two numbers.
If the above machinations result in a maximum value less than the minimum value, then the maximum value is actually the same as the minimum value.
If the value
attribute is
specified and a value could be parsed out of it, then that value
is the actual value.
If the value
attribute is
not specified but the max
attribute is specified and the result of processing the
textContent
of the element was one number with no
associated denominator punctuation character, then that number is
the actual value.
If neither of the value
and max
attributes are
specified, then, if the result of processing the
textContent
of the element was one number (with or
without an associated denominator punctuation character), then
that is the actual value, and if the result of processing the
textContent
of the element was two numbers, then the
actual value is the lower of the two numbers found.
Otherwise, if none of the above apply, the actual value is zero.
If the above procedure results in an actual value less than the minimum value, then the actual value is actually the same as the minimum value.
If, on the other hand, the result is an actual value greater than the maximum value, then the actual value is the maximum value.
If the low
attribute is
specified and a value could be parsed out of it, then the low
boundary is that value. Otherwise, the low boundary is the same as
the minimum value.
If the low boundary is then less than the minimum value, then the low boundary is actually the same as the minimum value. Similarly, if the low boundary is greater than the maximum value, then it is actually the maximum value instead.
If the high
attribute is
specified and a value could be parsed out of it, then the high
boundary is that value. Otherwise, the high boundary is the same
as the maximum value.
If the high boundary is then less than the low boundary, then the high boundary is actually the same as the low boundary. Similarly, if the high boundary is greater than the maximum value, then it is actually the maximum value instead.
If the optimum
attribute is specified and a value could be parsed out of it, then
the optimum point is that value. Otherwise, the optimum point is
the midpoint between the minimum value and the maximum value.
If the optimum point is then less than the minimum value, then the optimum point is actually the same as the minimum value. Similarly, if the optimum point is greater than the maximum value, then it is actually the maximum value instead.
All of which will result in the following inequalities all being true:
UA requirements for regions of the gauge: If the optimum point is equal to the low boundary or the high boundary, or anywhere in between them, then the region between the low and high boundaries of the gauge must be treated as the optimum region, and the low and high parts, if any, must be treated as suboptimal. Otherwise, if the optimum point is less than the low boundary, then the region between the minimum value and the low boundary must be treated as the optimum region, the region between the low boundary and the high boundary must be treated as a suboptimal region, and the region between the high boundary and the maximum value must be treated as an even less good region. Finally, if the optimum point is higher than the high boundary, then the situation is reversed; the region between the high boundary and the maximum value must be treated as the optimum region, the region between the high boundary and the low boundary must be treated as a suboptimal region, and the remaining region between the low boundary and the minimum value must be treated as an even less good region.
UA requirements for showing the gauge: When
representing a meter
element to the user, the UA should
indicate the relative position of the actual value to the minimum
and maximum values, and the relationship between the actual value
and the three regions of the gauge.
The following markup:
<h3>Suggested groups</h3> <menu type="toolbar"> <a href="?cmd=hsg" onclick="hideSuggestedGroups()">Hide suggested groups</a> </menu> <ul> <li> <p><a href="/group/comp.infosystems.www.authoring.stylesheets/view">comp.infosystems.www.authoring.stylesheets</a> - <a href="/group/comp.infosystems.www.authoring.stylesheets/subscribe">join</a></p> <p>Group description: <strong>Layout/presentation on the WWW.</strong></p> <p><meter value="0.5">Moderate activity,</meter> Usenet, 618 subscribers</p> </li> <li> <p><a href="/group/netscape.public.mozilla.xpinstall/view">netscape.public.mozilla.xpinstall</a> - <a href="/group/netscape.public.mozilla.xpinstall/subscribe">join</a></p> <p>Group description: <strong>Mozilla XPInstall discussion.</strong></p> <p><meter value="0.25">Low activity,</meter> Usenet, 22 subscribers</p> </li> <li> <p><a href="/group/mozilla.dev.general/view">mozilla.dev.general</a> - <a href="/group/mozilla.dev.general/subscribe">join</a></p> <p><meter value="0.25">Low activity,</meter> Usenet, 66 subscribers</p> </li> </ul>
Might be rendered as follows:
User agents may combine the value of the title
attribute and the other attributes
to provide context-sensitive help or inline text detailing the
actual values.
For example, the following snippet:
<meter min=0 max=60 value=23.2 title=seconds></meter>
...might cause the user agent to display a gauge with a tooltip saying "Value: 23.2 out of 60." on one line and "seconds" on a second line.
The min
, max
, value
, low
, high
, and optimum
DOM attributes
must reflect the respective content attributes of the
same name. When the relevant content attributes are absent, the DOM
attributes must return zero. The value parsed from the
textContent
never affects the DOM values.
Would be cool to have the value
DOM attribute update the
textContent
in-line...
code
elementHTMLElement
.The code
element represents a fragment
of computer code. This could be an XML element name, a filename, a
computer program, or any other string that a computer would
recognize.
Although there is no formal way to indicate the language of
computer code being marked up, authors who wish to mark
code
elements with the language used, e.g. so that
syntax highlighting scripts can use the right rules, may do so by
adding a class prefixed with "language-
" to
the element.
The following example shows how the element can be used in a paragraph to mark up element names and computer code, including punctuation.
<p>The <code>code</code> element represents a fragment of computer code.</p> <p>When you call the <code>activate()</code> method on the <code>robotSnowman</code> object, the eyes glow.</p> <p>The example below uses the <code>begin</code> keyword to indicate the start of a statement block. It is paired with an <code>end</code> keyword, which is followed by the <code>.</code> punctuation character (full stop) to indicate the end of the program.</p>
The following example shows how a block of code could be marked
up using the pre
and code
elements.
<pre><code class="language-pascal">var i: Integer; begin i := 1; end.</code></pre>
A class is used in that example to indicate the language used.
See the pre
element for more details.
var
elementHTMLElement
.The var
element represents a
variable. This could be an actual variable in a mathematical
expression or programming context, or it could just be a term used
as a placeholder in prose.
In the paragraph below, the letter "n" is being used as a variable in prose:
<p>If there are <var>n</var> pipes leading to the ice cream factory then I expect at <em>least</em> <var>n</var> flavours of ice cream to be available for purchase!</p>
For mathematics, in particular for anything beyond the simplest
of expressions, MathML is more appropriate. However, the
var
element can still be used to refer to specific
variables that are then mentioned in MathML expressions.
In this example, an equation is shown, with a legend that
references the variables in the equation. The expression itself is
marked up with MathML, but the variables are mentioned in the
figure's legend using var
.
<figure> <math> <mi>a</mi> <mo>=</mo> <msqrt> <msup><mi>b</mi><mn>2</mn></msup> <mi>+</mi> <msup><mi>c</mi><mn>2</mn></msup> </msqrt> </math> <legend> Using Pythagoras' theorem to solve for the hypotenuse <var>a</var> of a triangle with sides <var>b</var> and <var>c</var> </legend> </figure>
samp
elementHTMLElement
.The samp
element represents (sample)
output from a program or computing system.
See the pre
and kbd
elements for more details.
This example shows the samp
element being used
inline:
<p>The computer said <samp>Too much cheese in tray two</samp> but I didn't know what that meant.</p>
This second example shows a block of sample output. Nested
samp
and kbd
elements allow for the
styling of specific elements of the sample output using a
style sheet.
<pre><samp><samp class="prompt">jdoe@mowmow:~$</samp> <kbd>ssh demo.example.com</kbd> Last login: Tue Apr 12 09:10:17 2005 from mowmow.example.com on pts/1 Linux demo 2.6.10-grsec+gg3+e+fhs6b+nfs+gr0501+++p3+c4a+gr2b-reslog-v6.189 #1 SMP Tue Feb 1 11:22:36 PST 2005 i686 unknown <samp class="prompt">jdoe@demo:~$</samp> <samp class="cursor">_</samp></samp></pre>
kbd
elementHTMLElement
.The kbd
element represents user input
(typically keyboard input, although it may also be used to represent
other input, such as voice commands).
When the kbd
element is nested inside a
samp
element, it represents the input as it was echoed
by the system.
When the kbd
element contains a
samp
element, it represents input based on system
output, for example invoking a menu item.
When the kbd
element is nested inside another
kbd
element, it represents an actual key or other
single unit of input as appropriate for the input mechanism.
Here the kbd
element is used to indicate keys to press:
<p>To make George eat an apple, press <kbd><kbd>Shift</kbd>+<kbd>F3</kbd></kbd></p>
In this second example, the user is told to pick a particular
menu item. The outer kbd
element marks up a block of
input, with the inner kbd
elements representing each
individual step of the input, and the samp
elements
inside them indicating that the steps are input based on something
being displayed by the system, in this case menu labels:
<p>To make George eat an apple, select <kbd><kbd><samp>File</samp></kbd>|<kbd><samp>Eat Apple...</samp></kbd></kbd> </p>
sub
and sup
elementsHTMLElement
.The sup
element represents a
superscript and the sub
element represents
a subscript.
These elements must be used only to mark up typographical
conventions with specific meanings, not for typographical
presentation for presentation's sake. For example, it would be
inappropriate for the sub
and sup
elements
to be used in the name of the LaTeX document preparation system. In
general, authors should use these elements only if the
absence of those elements would change the meaning of the
content.
When the sub
element is used inside a
var
element, it represents the subscript that
identifies the variable in a family of variables.
<p>The coordinate of the <var>i</var>th point is (<var>x<sub><var>i</var></sub></var>, <var>y<sub><var>i</var></sub></var>). For example, the 10th point has coordinate (<var>x<sub>10</sub></var>, <var>y<sub>10</sub></var>).</p>
In certain languages, superscripts are part of the typographical conventions for some abbreviations.
<p>The most beautiful women are <span lang="fr"><abbr>M<sup>lle</sup></abbr> Gwendoline</span> and <span lang="fr"><abbr>M<sup>me</sup></abbr> Denise</span>.</p>
Mathematical expressions often use subscripts and superscripts.
Authors are encouraged to use MathML for marking up mathematics, but
authors may opt to use sub
and sup
if
detailed mathematical markup is not desired. [MathML]
<var>E</var>=<var>m</var><var>c</var><sup>2</sup>
f(<var>x</var>, <var>n</var>) = log<sub>4</sub><var>x</var><sup><var>n</var></sup>
span
elementHTMLElement
.The span
element doesn't mean anything on its own,
but can be useful when used together with other attributes,
e.g. class
, lang
, or dir
. It represents its
children.
i
elementHTMLElement
.The i
element represents a span of text
in an alternate voice or mood, or otherwise offset from the normal
prose, such as a taxonomic designation, a technical term, an
idiomatic phrase from another language, a thought, a ship name, or
some other prose whose typical typographic presentation is
italicized.
Terms in languages different from the main text should be
annotated with lang
attributes (xml:lang
in XML).
The examples below show uses of the i
element:
<p>The <i class="taxonomy">Felis silvestris catus</i> is cute.</p> <p>The term <i>prose content</i> is defined above.</p> <p>There is a certain <i lang="fr">je ne sais quoi</i> in the air.</p>
In the following example, a dream sequence is marked up using
i
elements.
<p>Raymond tried to sleep.</p> <p><i>The ship sailed away on Thursday</i>, he dreamt. <i>The ship had many people aboard, including a beautiful princess called Carey. He watched her, day-in, day-out, hoping she would notice him, but she never did.</i></p> <p><i>Finally one night he picked up the courage to speak with her—</i></p> <p>Raymond woke with a start as the fire alarm rang out.</p>
Authors are encouraged to use the class
attribute on the i
element to identify why the element is being used, so that if the
style of a particular use (e.g. dream sequences as opposed to
taxonomic terms) is to be changed at a later date, the author
doesn't have to go through the entire document (or series of related
documents) annotating each use. Similarly, authors are encouraged to
consider whether other elements might be more applicable than the
i
element, for instance the em
element for
marking up stress emphasis, or the dfn
element to mark
up the defining instance of a term.
Style sheets can be used to format i
elements, just like any other element can be restyled. Thus, it is
not the case that content in i
elements will
necessarily be italicized.
b
elementHTMLElement
.The b
element represents a span of text
to be stylistically offset from the normal prose without conveying
any extra importance, such as key words in a document abstract,
product names in a review, or other spans of text whose typical
typographic presentation is boldened.
The following example shows a use of the b
element
to highlight key words without marking them up as important:
<p>The <b>frobonitor</b> and <b>barbinator</b> components are fried.</p>
In the following example, objects in a text adventure are
highlighted as being special by use of the b
element.
<p>You enter a small room. Your <b>sword</b> glows brighter. A <b>rat</b> scurries past the corner wall.</p>
Another case where the b
element is appropriate is
in marking up the lede (or lead) sentence or paragraph. The
following example shows how a BBC
article about kittens adopting a rabbit as their own could be
marked up using HTML5 elements:
<article> <h2>Kittens 'adopted' by pet rabbit</h2> <p><b>Six abandoned kittens have found an unexpected new mother figure — a pet rabbit.</b></p> <p>Veterinary nurse Melanie Humble took the three-week-old kittens to her Aberdeen home.</p> [...]
The b
element should be used as a last resort when
no other element is more appropriate. In particular, headers should
use the h1
to h6
elements, stress emphasis
should use the em
element, importance should be denoted
with the strong
element, and text marked or highlighted
should use the mark
element.
The following would be incorrect usage:
<p><b>WARNING!</b> Do not frob the barbinator!</p>
In the previous example, the correct element to use would have
been strong
, not b
.
Style sheets can be used to format b
elements, just like any other element can be restyled. Thus, it is
not the case that content in b
elements will
necessarily be boldened.
bdo
elementdir
global attribute has special semantics on this element.HTMLElement
.The bdo
element represents explicit
text directionality formatting control for its children. It allows
authors to override the Unicode bidi algorithm by explicitly
specifying a direction override. [BIDI]
Authors must specify the dir
attribute on this element, with the value ltr
to
specify a left-to-right override and with the value rtl
to specify a right-to-left override.
If the element has the dir
attribute set to the exact value ltr
, then for the
purposes of the bidi algorithm, the user agent must act as if there
was a U+202D LEFT-TO-RIGHT OVERRIDE character at the start of the
element, and a U+202C POP DIRECTIONAL FORMATTING at the end of the
element.
If the element has the dir
attribute set to the exact value rtl
, then for the
purposes of the bidi algorithm, the user agent must act as if there
was a U+202E RIGHT-TO-LEFT OVERRIDE character at the start of the
element, and a U+202C POP DIRECTIONAL FORMATTING at the end of the
element.
The requirements on handling the bdo
element for the
bidi algorithm may be implemented indirectly through the style
layer. For example, an HTML+CSS user agent should implement these
requirements by implementing the CSS unicode-bidi
property. [CSS21]
ruby
elementrt
element, or an rp
element, an rt
element, and another rp
element.HTMLElement
.The ruby
element allows one or more spans of
phrasing content to be marked with ruby annotations. Ruby
annotations are short runs of text presented alongside base text,
primarily used in East Asian typography as a guide for
pronounciation or to include other annotations. In Japanese, this
form of typography is also known as furigana.
A ruby
element represents the spans of
phrasing content it contains, ignoring all the child rt
and rp
elements and their descendants. Those spans of
phrasing content have associated annotations created using the
rt
element.
In this example, each ideograph in the Japanese text 漢字 is annotated with its kanji reading.
...
<ruby>
漢 <rt> かん </rt>
字 <rt> じ </rt>
</ruby>
...
This might be rendered as:
In this example, each ideograph in the traditional Chinese text 漢字 is annotated with its bopomofo reading.
<ruby>
漢 <rt> ㄏㄢˋ </rt>
字 <rt> ㄗˋ </rt>
</ruby>
This might be rendered as:
In this example, each ideograph in the simplified Chinese text 汉字 is annotated with its pinyin reading.
...
<ruby>
汉 <rt> hàn </rt>
字 <rt> zì </rt>
</ruby>
...
This might be rendered as:
rt
elementruby
element.HTMLElement
.The rt
element marks the ruby text component of a
ruby annotation.
An rt
element that is a child of a ruby
element represents an annotation (given by its
children) for the zero or more nodes of phrasing content that
immediately precedes it in the ruby
element, ignoring
rp
elements.
An rt
element that is not a child of a
ruby
element represents the same thing as its
children.
rp
elementruby
element, either immediately before or immediately after an rt
element.rp
element is immediately after an rt
element that is immediately preceded by another rp
element: a single character from Unicode character class Pe.HTMLElement
.The rp
element can be used to provide parentheses
around a ruby text component of a ruby annotation, to be shown by
user agents that don't support ruby annotations.
An rp
element that is a child of a ruby
element represents nothing and it and its contents must
be ignored. An rp
element whose parent element is not a
ruby
element represents its children.
The example above, in which each ideograph in the text 漢字 is annotated with its kanji
reading, could be expanded to use rp
so that in legacy
user agents the readings are in parentheses:
...
<ruby>
漢 <rp>(</rp><rt>かん</rt><rp>)</rp>
字 <rp>(</rp><rt>じ</rt><rp>)</rp>
</ruby>
...
In conforming user agents the rendering would be as above, but in user agents that do not support ruby, the rendering would be:
... 漢 (かん) 字 (じ) ...
We need to summarize the various elements, in particular to distinguish b/i/em/strong/var/q/mark/cite.
HTML does not have a dedicated mechanism for marking up footnotes. Here are the recommended alternatives.
For short inline annotations, the title
attribute should be used.
In this example, two parts of a dialog are annotated.
<dialog> <dt>Customer <dd>Hello! I wish to register a complaint. Hello. Miss? <dt>Shopkeeper <dd><span title="Colloquial pronunciation of 'What do you'" >Watcha</span> mean, miss? <dt>Customer <dd>Uh, I'm sorry, I have a cold. I wish to make a complaint. <dt>Shopkeeper <dd>Sorry, <span title="This is, of course, a lie.">we're closing for lunch</span>. </dialog>
For longer annotations, the a
element should be
used, pointing to an element later in the document. The convention
is that the contents of the link be a number in square brackets.
In this example, a footnote in the dialog links to a paragraph below the dialog. The paragraph then reciprocally links back to the dialog, allowing the user to return to the location of the footnote.
<dialog> <dt>Announcer <dd>Number 16: The <i>hand</i>. <dt>Interviewer <dd>Good evening. I have with me in the studio tonight Mr Norman St John Polevaulter, who for the past few years has been contradicting people. Mr Polevaulter, why <em>do</em> you contradict people? <dt>Norman <dd>I don't. <a href="#fn1" id="r1">[1]</a> <dt>Interviewer <dd>You told me you did! </dialog> <section> <p id="fn1"><a href="#r1">[1]</a> This is, naturally, a lie, but paradoxically if it were true he could not say so without contradicting the interviewer and thus making it false.</p> </section>
For side notes, longer annotations that apply to entire sections
of the text rather than just specific words or sentences, the
aside
element should be used.
In this example, a sidebar is given after a dialog, giving some context to the dialog.
<dialog> <dt>Customer <dd>I will not buy this record, it is scratched. <dt>Shopkeeper <dd>I'm sorry? <dt>Customer <dd>I will not buy this record, it is scratched. <dt>Shopkeeper <dd>No no no, this's'a tobacconist's. </dialog> <aside> <p>In 1970, the British Empire lay in ruins, and foreign nationalists frequented the streets — many of them Hungarians (not the streets — the foreign nationals). Sadly, Alexander Yalt has been publishing incompetently-written phrase books. </aside>
The ins
and del
elements represent
edits to the document.
ins
elementcite
datetime
HTMLModElement
interface.The ins
element represents an addition
to the document.
The following represents the addition of a single paragraph:
<aside> <ins> <p> I like fruit. </p> </ins> </aside>
As does this, because everything in the aside
element here counts as phrasing content and therefore
there is just one paragraph:
<aside> <ins> Apples are <em>tasty</em>. </ins> <ins> So are pears. </ins> </aside>
ins
elements should not cross implied paragraph boundaries.
The following example represents the addition of two paragraphs,
the second of which was inserted in two parts. The first
ins
element in this example thus crosses a paragraph
boundary, which is considered poor form.
<aside> <ins datetime="2005-03-16T00:00Z"> <p> I like fruit. </p> Apples are <em>tasty</em>. </ins> <ins datetime="2007-12-19T00:00Z"> So are pears. </ins> </aside>
Here is a better way of marking this up. It uses more elements, but none of the elements cross implied paragraph boundaries.
<aside> <ins datetime="2005-03-16T00:00Z"> <p> I like fruit. </p> </ins> <ins datetime="2005-03-16T00:00Z"> Apples are <em>tasty</em>. </ins> <ins datetime="2007-12-19T00:00Z"> So are pears. </ins> </aside>
del
elementcite
datetime
HTMLModElement
interface.The del
element represents a removal
from the document.
del
elements should not cross implied paragraph boundaries.
ins
and del
elementsThe cite
attribute
may be used to specify the address of a document that explains the
change. When that document is long, for instance the minutes of a
meeting, authors are encouraged to include a fragment identifier
pointing to the specific part of that document that discusses the
change.
If the cite
attribute is
present, it must be a valid URL that explains the
change. To obtain the corresponding citation link, the value of the
attribute must be resolved
relative to the element. User agents should allow users to follow
such citation links.
The datetime
attribute may be used to specify the time and date of the change.
If present, the datetime
attribute must be a valid global date and time string
value.
User agents must parse the datetime
attribute according to the
parse a global date and time string algorithm. If that
doesn't return a time, then the modification has no associated
timestamp (the value is non-conforming; it is not a valid
global date and time string). Otherwise, the modification is
marked as having been made at the given datetime. User agents should
use the associated timezone information to determine which timezone
to present the given datetime in.
The ins
and del
elements must implement
the HTMLModElement
interface:
interface HTMLModElement : HTMLElement { attribute DOMString cite; attribute DOMString dateTime; };
The cite
DOM
attribute must reflect the element's cite
content attribute. The dateTime
DOM attribute
must reflect the element's datetime
content attribute.
Since the ins
and del
elements do not
affect paragraphing, it is possible,
in some cases where paragraphs are implied (without explicit p
elements), for an ins
or del
element to
span both an entire paragraph or other non-phrasing
content elements and part of another paragraph.
For example:
<section> <ins> <p> This is a paragraph that was inserted. </p> This is another paragraph whose first sentence was inserted at the same time as the paragraph above. </ins> This is a second sentence, which was there all along. </section>
By only wrapping some paragraphs in p
elements, one
can even get the end of one paragraph, a whole second paragraph,
and the start of a third paragraph to be covered by the same
ins
or del
element (though this is very
confusing, and not considered good practice):
<section> This is the first paragraph. <ins>This sentence was inserted. <p>This second paragraph was inserted.</p> This sentence was inserted too.</ins> This is the third paragraph in this example. </section>
However, due to the way implied
paragraphs are defined, it is not possible to mark up the
end of one paragraph and the start of the very next one using the
same ins
or del
element. You instead have
to use one (or two) p
element(s) and two
ins
or del
elements:
For example:
<section> <p>This is the first paragraph. <del>This sentence was deleted.</del></p> <p><del>This sentence was deleted too.</del> That sentence needed a separate <del> element.</p> </section>
Partly because of the confusion described above, authors are
strongly recommended to always mark up all paragraphs with the
p
element, and to not have any ins
or
del
elements that cross across any implied paragraphs.
The content models of the ol
and ul
elements do not allow ins
and del
elements
as children. Lists always represent all their items, including items
that would otherwise have been marked as deleted.
To indicate that an item is inserted or deleted, an
ins
or del
element can be wrapped around
the contents of the li
element. To indicate that an
item has been replaced by another, a single li
element
can have one or more del
elements followed by one or
more ins
elements.
In the following example, a list that started empty had items added and removed from it over time. The bits in the example that have been emphasised show the parts that are the "current" state of the list. The list item numbers don't take into account the edits, though.
<h1>Stop-ship bugs</h1> <ol> <li><ins datetime="2008-02-12T15:20Z">Bug 225: Rain detector doesn't work in snow</ins></li> <li><del datetime="2008-03-01T20:22Z"><ins datetime="2008-02-14T12:02Z">Bug 228: Water buffer overflows in April</ins></del></li> <li><ins datetime="2008-02-16T13:50Z">Bug 230: Water heater doesn't use renewable fuels</ins></li> <li><del datetime="2008-02-20T21:15Z"><ins datetime="2008-02-16T14:25Z">Bug 232: Carbon dioxide emissions detected after startup</ins></del></li> </ol>
In the following example, a list that started with just fruit was replaced by a list with just colors.
<h1>List of <del>fruits</del><ins>colors</ins></h1> <ul> <li><del>Lime</del><ins>Green</ins></li> <li><del>Apple</del></li> <li>Orange</li> <li><del>Pear</del></li> <li><ins>Teal</ins></li> <li><del>Lemon</del><ins>Yellow</ins></li> <li>Olive</li> <li><ins>Purple</ins> </ul>