download - Indicates to download the linked resource
instead of navigating to it. If the attribute has a set value, change the resource's proposed filename to the set value.
<{a/ping}> — URLs of the resources that are interested in being notified
<{a/rel}> — Relationship of this document (or subsection/topic) to the destination resource
<{a/rev}> — Reverse link relationship of the destination resource to this document (or subsection/topic)
hreflang - Language of the linked resource
type - Hint for the type of the referenced resource
If the <{a}> element has an <{a/href}> attribute, then it represents a
hyperlink (a hypertext anchor) labeled by its contents.
If the <{a}> element has no <{a/href}> attribute, then the element
represents a placeholder for where a link might otherwise have been placed, if it had been
relevant, consisting of just the element's contents.
The target, download, <{a/rel}>, <{a/rev}>, hreflang,
type, and referrerpolicy attributes must be omitted if the
<{a/href}> attribute is not present.
If a site uses a consistent navigation toolbar on every page, then the link that would
normally link to the page itself could be marked up using an <{a}> element:
The <{a/href}>, target, download, and referrerpolicy
attributes affect what happens when users follow hyperlinks or download hyperlinks
created using the <{a}> element. The <{a/rel}>, <{a/rev}>, 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 create hyperlinks is to
run the following steps:
1. If the <{a}> element's {{Document}} is not fully active, then abort
these steps.
2. If either the <{a}> element has a download attribute and the algorithm
is not allowed to show a popup, or the element's target attribute is
present and applying
the rules for choosing a browsing context given a browsing context name, using the
value of the target attribute as the browsing context name, would result
in there not being a chosen browsing context, then run these substeps:
1. If there is an entry settings object, throw an {{InvalidAccessError}}
exception.
2. Abort these steps without following the hyperlink.
3. If the target of the click event is an <{img}> element with an
<{img/ismap}> attribute specified, then server-side image map processing must be
performed, as follows:
1. If the click event was 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
to the location of the click, and let |y| be the distance
in CSS pixels from the top edge of the image
to the location of the click. Otherwise, let |x|
and |y| be zero.
2. Let hyperlink suffix be a U+003F QUESTION MARK character, the value of
x expressed as a base-ten integer using ASCII digits, a U+002C COMMA
character (,), and the value of y expressed as a base-ten integer using
ASCII digits.
4. Finally, the user agent must follow the hyperlink or download the hyperlink
created by the <{a}> element, as determined by the download attribute
and any expressed user preference, passing hyperlink suffix, if the steps above
defined it.
a . text
Same as {{Node/textContent}}.
The IDL attributes download,
target,
rel,
rev,
hreflang, and
type, must reflect the
respective content attributes of the same name.
The IDL attribute relList must
reflect the <{a/rel}> content attribute.
The IDL attribute referrerPolicy must reflect the
referrerpolicy content attribute, limited to only known values.
The text IDL attribute, on getting,
must return the same value as the {{Node/textContent}} IDL attribute on the element, and on
setting, must act as if the {{Node/textContent}} IDL attribute on the element had been set to
the new value.
The <{a}> element also supports the HTMLHyperlinkElementUtils interface. [[!URL]]
When the element is created, and whenever the element's <{links/href}> content attribute is
set, changed, or removed, the user agent must invoke the element's HTMLHyperlinkElementUtils
interface's set the input algorithm with the value of the <{links/href}> content
attribute, if any, or the empty string otherwise, as the given value.
The element's HTMLHyperlinkElementUtils interface's get the base algorithm must simply return
the document base URL.
The element's HTMLHyperlinkElementUtils interface's query encoding is the
document's character encoding.
When the element's HTMLHyperlinkElementUtils interface invokes its update steps with a string
value, the user agent must set the element's <{links/href}> content attribute to
the string value.
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:
The <{em}> element represents stress emphasis of its contents.
The level of stress that a particular piece of content has is given by its number of ancestor
<{em}> elements.
The placement of stress emphasis changes the meaning of the sentence. The element thus forms an
integral part of the content. The precise way in which stress is used in this way depends on the
language.
These examples show how changing the stress emphasis changes the meaning. First, a general
statement of fact, with no stress:
Cats are cute animals.
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):
Cats are cute animals.
Moving the stress to the verb, one highlights that the truth of the entire sentence is in
question (maybe someone is saying cats are not cute):
Cats are cute animals.
By moving it to the adjective, the exact nature of the cats is reasserted (maybe someone
suggested cats were mean animals):
Cats are cute animals.
Similarly, if someone asserted that cats were vegetables, someone correcting this might
emphasize the last word:
Cats are cute animals.
By emphasizing the entire sentence, it becomes clear that the speaker is fighting hard to get
the point across. This kind of stress emphasis also typically affects the punctuation, hence the
exclamation mark here.
Cats are cute animals!
Anger mixed with emphasizing the cuteness could lead to markup such as:
Cats are cute animals!
The <{em}> element isn't a generic "italics" element. Sometimes, text is intended to
stand out from the rest of the paragraph, as if it was in a different mood or voice. For this,
the <{i}> element is more appropriate.
The <{em}> element also isn't intended to convey importance; for that purpose, the
<{strong}> element is more appropriate.
The <{strong}> element represents strong importance, seriousness, or
urgency for its contents.
Importance: The <{strong}> element can be used in a heading, caption,
or paragraph to distinguish the part that really matters from other parts that might be more
detailed, more jovial, or merely boilerplate.
For example, the first word of the previous paragraph is marked up with
strong to distinguish it from the more detailed text in the rest of the
paragraph.
Seriousness: The <{strong}> element can be used to mark up a warning
or caution notice.
Urgency: The <{strong}> element can be used to denote contents that
the user needs to see sooner than other parts of the document.
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, the word "chapter" and the actual chapter number are mere boilerplate, and the actual
name of the chapter is marked up with strong:
Chapter 1: The Praxis
In the following example, the name of the diagram in the caption is marked up with
<{strong}>, to distinguish it from boilerplate text (before) and the description
(after):
Figure 1. Ant colony dynamics. The ants in this colony are affected by the heat source (upper left) and the food source (lower right).
In this example, the heading is really "Flowers, Bees, and Honey", but the author has added a
light-hearted addition to the heading. The <{strong}> element is thus used to mark up
the first part to distinguish it from the latter part.
Flowers, Bees, and Honey and other things I don't understand
Here is an example of a warning notice in a game, with the
various parts marked up according to how important they are:
Warning. This dungeon is dangerous.
Avoid the ducks. Take any gold you find.
Do not take any of the diamonds, they are explosive and will destroy anything within ten meters. You have been warned.
In this example, the <{strong}> element is used to denote the part of the text that
the user is intended to read first.
The <{small}> element represents side comments such as small print.
Small print typically features disclaimers, caveats, legal restrictions, or copyrights. Small
print is also sometimes used for attribution, or for satisfying licensing requirements.
The <{small}> element does not "de-emphasize" or lower the importance of text
emphasized by the <{em}> element or marked as important with the strong
element. To mark text as not emphasized or important, simply do not mark it up with the
em or <{strong}> elements respectively.
The <{small}> element should not be used for extended spans of text, such as multiple
paragraphs, lists, or sections of text. It is only intended for short runs of text. The text of a
page listing terms of use, for instance, would not be a suitable candidate for the
<{small}> element: in such a case, the text is not a side comment, it is the main content
of the page.
In this example, the <{small}> element is used to indicate that value-added tax is
not included in a price of a hotel room:
Single room
199 € breakfast included, VAT not included
Double room
239 € breakfast included, VAT not included
In this second example, the <{small}> element is used for a side comment in an article.
Example Corp today announced record profits for the second quarter (Full Disclosure: Foo News is a subsidiary of Example Corp), leading to speculation about a third quarter merger with Demo Group.
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.
In this last example, the <{small}> element is marked as being important
small print.
Continued use of this service will result in a kiss.
The <{s}> element represents contents that are no longer accurate or no longer
relevant.
The <{s}> element is not appropriate when indicating document edits; to mark a span of
text as having been removed from a document, use the <{del}> element.
In this example a recommended retail price has been marked as no longer relevant as the product
in question has a new sale price.
The <{cite}> element represents a reference to a creative work. It must include
the title of the work or the name of the author (person, people or organization) or an URL
reference, or a reference in abbreviated form as per the conventions used for the addition of
citation metadata.
Creative works include 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, a legal case report, a computer program, a web site, a web page, a blog post or
comment, a forum post or comment, a tweet, a written or oral statement, etc.
Here is an example of the author of a quote referenced using the <{cite}> element:
In the words of Charles Bukowski -
An intellectual says a simple thing in a hard way. An artist says a hard thing in a simple way.
This second example identifies the author of a tweet by referencing the authors name using the <{cite}> element:
This is for everyone #london2012 #oneweb #openingceremony @webfoundation @w3c
In this example the <{cite}> element is used to reference the title of a work in a
bibliography:
Universal Declaration of Human Rights, United Nations, December 1948. Adopted by General Assembly resolution 217 A (III).
In this example the <{cite}> element is used to reference the title of a television
show:
Who is your favorite doctor (in Doctor Who)?
A very common use for the <{cite}> element is to identify the author of a comment in a
blog post or forum, as in this example:
Comment by Elizabeth Bennet
There is a stubbornness about me that never can bear to be frightened at the will of others. My courage always rises at every attempt to intimidate me
Another common use for the <{cite}> element is to reference the URL
of a search result, as in this example:
15 Apr 2013 - The HTML Working Group is currently chartered to continue its work through 31 December 2014. A Plan 2014 document published by the...
...
Where the <{cite}> element is used to identify an abbreviated reference such as
Ibid. it is suggested that this reference be linked to the base reference:
Book notes
"Money is the real cause of poverty,"
"Money is the cause of poverty because it is the device by which those who are too lazy to work are enabled to rob the workers of the fruits of their labour."
Ibid.
A citation is not a quote (for which the <{q}> element is
appropriate).
This is incorrect usage, because <{cite}> is not for quotes:
This is wrong!, said Hillary. is a quote from the popular daytime TV drama When Ian became Hillary.
This is an example of the correct usage:
This is correct, said Hillary. is a quote from the popular daytime TV drama When Ian became Hillary.
The <{q}> element represents some phrasing content quoted from another source.
Quotation punctuation (such as quotation marks) that is quoting the contents of the element 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, may be cited in the cite attribute. The source may be fictional,
as when quoting characters in a novel or screenplay.
If the <{q/cite}> attribute is present, it must be a
valid URL potentially surrounded by spaces. To obtain the corresponding citation link, the
value of the attribute must be parsed relative to the element's node document.
User agents may allow users to follow such citation links, but they are primarily intended for
private use (e.g., by server-side scripts collecting statistics about a site's use of quotations),
not for readers.
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:
The man said Things that are impossible just take longer. I disagreed with him.
Here is an example with both an explicit citation link in the <{q}> element, and an
explicit citation outside:
The W3C page About W3C says the W3C's mission is To lead the World Wide Web to its full potential by developing protocols and guidelines that ensure long-term growth for the Web. I fully agree with this mission.
In the following example, the quotation itself contains a quotation:
In Example One, he writes The man said Things that are impossible just take longer. I disagreed with him. Well, I disagree even more!
In the following example, quotation marks are used instead of the <{q}> element:
His best argument was ❝I disagree❞, which I thought was laughable.
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.
The word "ineffable" could have been used to describe the disaster resulting from the campaign's mismanagement.
The <{dfn}> element represents the defining instance of a term. The
term-description group, <{p}>, <{li}> or <{section}> element 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 <{abbr/title}> attribute, then the exact value
of that attribute is the term being defined. Otherwise, it is the exact
{{Node/textContent}} of the <{dfn}> element that gives the term being defined.
If the <{dfn/title}> attribute of the <{dfn}> element is present, then it must
contain only the term being defined.
The <{global/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 "Garage Door Opener" is first defined in the first
paragraph, then used in the second. In both cases, its abbreviation is what is actually
displayed.
The GDO is a device that allows off-world teams to open the iris.
Teal'c activated his GDO and so Hammond ordered the iris to be opened.
With the addition of an <{a}> element, the reference can be made explicit:
The GDO is a device that allows off-world teams to open the iris.
Teal'c activated his GDO and so Hammond ordered the iris to be opened.
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".
The W3C is the main international standards organization for the World Wide Web.
An alternative way to write this would be:
The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web.
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.
The W3C started working on HTML in 1994.
This paragraph links an abbreviation to its definition.
This paragraph marks up an abbreviation without giving an expansion, possibly as a hook to
apply styles for abbreviations (e.g., smallcaps).
There are several W3C offices around the world.
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:
Two WGs worked on this specification: the CSSWG and the ARIA.
Here the plural is inside the element, so the expansion is in the plural:
Two WGs worked on this specification: the CSSWG and the ARIA.
Abbreviations do not have to be marked up using this element. It is expected to be useful in the
following cases:
* Abbreviations for which the author wants to give expansions, where using the <{abbr}>
element with a <{abbr/title}> attribute is an alternative to including the expansion inline
(e.g., in parentheses).
* Abbreviations that are likely to be unfamiliar to the document's readers, for which authors are
encouraged to either mark up the abbreviation using an <{abbr}> element with a
<{abbr/title}> attribute or include the expansion inline in the text the first time the
abbreviation is used.
* Abbreviations whose presence needs to be semantically annotated, e.g., so that they can be
identified from a style sheet and given specific styles, for which the <{abbr}> element
can be used without a <{abbr/title}> attribute.
Providing an expansion in a <{abbr/title}> attribute once will not necessarily cause other
<{abbr}> elements in the same document with the same contents but without a
<{abbr/title}> attribute to behave as if they had the same expansion. Every <{abbr}>
element is independent.
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 pronunciation or to include other annotations. In
Japanese, this form of typography is also known as furigana. Ruby text can appear on either
side, and sometimes both sides, of the base text, and it is possible to control its position using
CSS. A more complete introduction to ruby can be found in the Use Cases & Exploratory
Approaches for Ruby Markup document as well as in CSS Ruby.
[[RUBY-UC]] [[CSS3-RUBY]]
The content model of <{ruby}> elements consists of one or more of the following sequences:
1. One or more phrasing content nodes or <{rb}> elements.
2. One or more rt or <{rtc}> elements, each of which either immediately
preceded or followed by an <{rp}> elements.
The <{ruby}>, <{rb}>, <{rtc}>, and <{rt}> elements can be used
for a variety of kinds of annotations, including in particular (though by no means limited to)
those described below. For more details on Japanese Ruby in particular, and how to render Ruby for
Japanese, see Requirements for Japanese Text Layout. [[!JLREQ]] The rp
element can be used as fallback content when ruby rendering is not supported.
: Mono-ruby for individual base characters
:: Annotations (the ruby text) are associated individually with each ideographic character (the
base text). In Japanese this is typically hiragana or katakana characters used to provide
readings of kanji characters.
base
When no <{rb}> element is used, the base is implied, as above. But you can also make
it explicit. This can be useful notably for styling, or when consecutive bases are to be
treated as a group, as in the jukugo ruby example further down.
base
In the following example, notice how each annotation corresponds to a single base character.
日本
語で書 いた
作文です。
Ruby text interspersed in regular text provides structure akin to the following image:
This example can also be written as follows, using one <{ruby}> element with two
segments of base text and two annotations (one for each) rather than two back-to-back
<{ruby}> elements each with one base text segment and annotation (as in the markup
above):
日本語
で書
いた作文です。
: Group ruby
:: Group ruby is often used where phonetic annotations don't map to discreet base characters, or
for semantic glosses that span the whole base text. For example, the word "today" is written
with the characters 今日, literally "this day". But it's pronounced きょう (kyou), which
can't be broken down into a "this" part and a "day" part. In typical rendering, you can't
split text that is annotated with group ruby; it has to wrap as a single unit onto the next
line. When a ruby text annotation maps to a base that is comprised of more than one
character, then that base is grouped.
The following group ruby:
Can be marked up as follows:
今日
: Jukugo ruby
:: Jukugo refers to a Japanese compound noun, i.e., a word made up of more than one
kanji character. Jukugo ruby is a term that is used not to describe ruby
annotations over jukugo text, but rather to describe ruby with a behavior slightly
different from mono or group ruby. Jukugo ruby is similar to mono ruby, in that there is
a strong association between ruby text and individual base characters, but the ruby text
is typically rendered as grouped together over multiple ideographs when they are on the
same line.
The distinction is captured in this example:
Which can be marked up as follows:
法華経
In this example, each <{rt}> element is paired with its respective rb
element, the difference with an interleaved rb/rt approach being
that the sequences of both base text and ruby annotations are implicitly placed in common
containers so that the grouping information is captured.
For more details on Jukugo Ruby rendering, see Appendix F in the
Requirements for Japanese Text Layout and Use Case C: Jukugo ruby in the
Use Cases & Exploratory Approaches for Ruby Markup. [[!JLREQ]]
[[RUBY-UC]]
: Inline ruby
:: In some contexts, for instance when the font size or line height are too small for ruby to be
readable, it is desirable to inline the ruby annotation such that it appears in parentheses
after the text it annotates. This also provides a convenient fallback strategy for user
agents that do not support rendering ruby annotations.
Inlining takes grouping into account. For example, Tokyo is written with two kanji
characters, 東, which is pronounced とう, and 京, which is pronounced きょう. Each base
character should be annotated individually, but the fallback should be 東京(とうきょう) not
東(とう)京(きょう). This can be marked up as follows:
東京とうきょう
Note that the above markup will enable the usage of parentheses when inlining for browsers
that support ruby layout, but for those that don't it will fail to provide parenthetical
fallback. This is where the <{rp}> element is useful. It can be inserted into the
above example to provide the appropriate fallback when ruby layout is not supported:
東京
: Text with both phonetic and semantic annotations (double-sided ruby)
:: Sometimes, ruby can be used to annotate a base twice.
In the following example, the Chinese word for San Francisco (旧金山, i.e., "old gold
mountain") is annotated both using pinyin to give the pronunciation, and with the original
English.
Which is marked up as follows:
旧金山jiùjīnshān
In this example, a single base run of three base characters is annotated with three pinyin
ruby text segments in a first (implicit) container, and an <{rtc}> element is
introduced in order to provide a second single ruby text annotation being the
city's English name.
We can also revisit our jukugo example above with 上手 ("skill") to show how it can be
annotation in both kana and romaji phonetics while at the same time maintaining the
pairing to bases and annotation grouping information.
Which is marked up as follows:
上手じようず
Text that is a direct child of the <{rtc}> element implicitly produces a ruby text
segment as if it were contained in an <{rt}> element. In this contrived example,
this is shown with some symbols that are given names in English and French with annotations
intended to appear on either side of the base symbol.
♥Heart
☘Shamrock
✶Star
Similarly, text directly inside a <{ruby}> element implicitly produces a ruby base
as if it were contained in an <{rb}> element, and rt children of
ruby are implicitly contained in an rtc container. In effect, the
above example is equivalent (in meaning, though not in the DOM it produces) to the
following:
♥☘✶
Within a ruby element, content is parcelled into a series of ruby segments. Each
ruby segment is described by:
* Zero or more ruby bases, each of which is a DOM range that may contain phrasing
content or an <{rb}> element.
* A base range, that is a DOM range including all the bases. This is the
ruby base container.
* Zero or more ruby text containers which may correspond to explicit rtc
elements, or to sequences of <{rt}> elements implicitly recognized as contained
in an anonymous ruby text container.
Each ruby text container is described by zero or more
ruby text annotations each of which is a DOM range that may contain phrasing content
or an <{rt}> element, and an annotations range that is a range including all the
annotations for that container. A ruby text container is also known (primarily in a CSS
context) as a ruby annotation container.
Furthermore, a ruby element contains ignored ruby content. Ignored ruby content does
not form part of the document's semantics. It consists of some inter-element white space
and <{rp}> elements, the latter of which are used for legacy user agents that do not
support ruby at all.
The process of annotation pairing associates ruby annotations with
ruby bases. Within each ruby segment, each ruby base in the
ruby base container is paired with one ruby text annotation from the
ruby text container, in order. If there are not enough ruby text annotations in a
ruby annotation container, the last one is associated with any excess ruby bases.
(If there are not any in the ruby annotation container, an anonymous empty one is assumed
to exist.) If there are not enough ruby bases, any remaining ruby text annotations
are assumed to be associated with empty, anonymous bases inserted at the end of the
ruby base container.
Note that the terms ruby segment, ruby base, ruby text annotation,
ruby text container, ruby base container, and ruby annotation container
have their equivalents in CSS Ruby Module Level 3. [[CSS3-RUBY]]
Informally, the segmentation and categorization algorithm below performs a simple set of
tasks. First it processes adjacent <{rb}> elements, text nodes, and non-ruby
elements into a list of bases. Then it processes any number of <{rtc}> elements or
sequences of <{rt}> elements that are considered to automatically map to an
anonymous ruby text container. Put together these data items form a ruby
segment as detailed in the data model above. It will continue to produce such segments
until it reaches the end of the content of a given <{ruby}> element. The complexity
of the algorithm below compared to this informal description stems from the need to support
an author-friendly syntax and being mindful of inter-element white space.
At any particular time, the segmentation and categorization of content of a
ruby element is the result that would be obtained from running the following
algorithm:
Let root be the <{ruby}> element for which the algorithm is
being run.
Let index be 0.
Let ruby segments be an empty list.
Let current bases be an empty list of DOM ranges.
Let current bases range be null.
Let current bases range start be null.
Let current annotations be an empty list of DOM ranges.
Let current annotations range be null.
Let current annotations range start be null.
Let current annotation containers be an empty list.
Let current automatic base nodes be an empty list of DOM Nodes.
Let current automatic base range start be null.
Process a ruby child: If index is equal to or greater than the number of
child nodes in root, then run the steps to commit a ruby segment,
return ruby segments, and abort these steps.
Let current child be the indexth node in root.
If current child is not a Text node and is not an
{{Element}} node, then increment index by one and jump to the step
labelled process a ruby child.
If current child is an <{rp}> element, then increment
index by one and jump to the step labelled process a ruby child. (Note
that this has the effect of including this element in any range that we are currently
processing. This is done intentionally so that misplaced rp can be
processed correctly; semantically they are ignored all the same.)
If current child is an <{rt}> element, then run these substeps:
If current annotations is empty, set current annotations range
start to the value of index.
Create a new DOM range whose start is the
boundary point (root,
index) and whose end is the boundary point (root, index plus
one), and append it at the end of current annotations.
Increment index by one and jump to the step labelled process a ruby
child.
If current child is an <{rtc}> element, then run these
substeps:
If current annotations is not empty, increment index by one and
jump to the step labelled process a ruby child.
Run the following substeps:
Let lookahead index be set to the value of index.
Peek ahead: Increment lookahead index by one.
If lookahead index is equal to or greater than the number of
child nodes in root, then abort these substeps.
Let peek child be the lookahead indexth node in
root.
If peek child is a {{Text}} node and is inter-element
white space, then jump to the step labelled peek ahead.
If peek child is an <{rt}> element, an
<{rtc}> element, or an <{rp}> element, then set
index to the value of lookahead index and jump to the step
labelled process a ruby child.
If current annotations is not empty or if current annotation
containers is not empty, then run the steps to commit a ruby segment.
If current child is an <{rb}> element, then run these substeps:
If current bases is empty, then set current bases range start to
the value of index.
Create a new DOM range whose start is the
boundary point (root,
index) and whose end is the boundary point (root, index plus
one), and append it at the end of current bases.
Increment index by one and jump to the step labelled process a ruby
child.
If current automatic base nodes is empty, set current automatic base range
start to the value of index.
Append current child at the end of current automatic base nodes.
Increment index by one and jump to the step labelled process a ruby
child.
When the steps above say to commit a ruby segment, it means to run the
following steps at that point in the algorithm:
Create a new ruby segment. It is described by a list of bases set to
current bases, a base DOM range set to current bases range, and a
list of ruby annotation containers
that are the current annotation containers list. Append this new
ruby segment at the end of ruby segments.
Let current bases be an empty list.
Let current bases range be null.
Let current bases range start be null.
Let current annotation containers be an empty list.
When the steps above say to commit the base range, it means to run the following
steps at that point in the algorithm:
If current bases is empty, abort these steps.
If current bases range is not null, abort these steps.
Let current bases range be a DOM range whose start is the boundary
point (root, current bases range start) and whose end is the boundary
point (root, index).
When the steps above say to commit current annotations, it means to run the
following steps at that point in the algorithm:
If current annotations is not empty and current annotations range is
null let current annotations range be a DOM range whose start is the boundary
point (root, current annotations range start) and whose end is the boundary
point (root, index).
If current annotations is not empty, create a new ruby annotation
container. It is described by an annotations list set to current
annotations and a range set to current annotations range. Append this new
ruby annotation container at the end of current annotation
containers.
Let current annotations be an empty list of DOM ranges.
Let current annotations range be null.
Let current annotations range start be null.
When the steps above say to commit an automatic base, it means to run the
following steps at that point in the algorithm:
If current automatic base nodes is empty, abort these steps.
If current automatic base nodes contains nodes that are not {{Text}}
nodes, or {{Text}} nodes that are not inter-element white space, then
run these substeps:
It current bases is empty, set current bases range start to the
value of current automatic base range start.
Create a new DOM range whose start is the
boundary point (root, current
automatic base range start) and whose end
is the boundary point (root,
index), and append it at the end of current bases.
Let current automatic base nodes be an empty list of DOM Nodes.
An <{rb}> element's end tag may be omitted if the <{rb}> element is
immediately followed by an <{rb}>, <{rt}>, rtc or
<{rp}> element, or if there is no more content in the parent element.
The <{rb}> element marks the base text component of a ruby annotation. When it is
the child of a <{ruby}> element, it doesn't represent anything itself, but its parent ruby
element uses it as part of determining what itrepresents.
An <{rb}> element that is not a child of a <{ruby}> element represents
the same thing as its children.
An <{rt}> element's end tag may be omitted if the <{rt}> element is
immediately followed by an <{rb}>, <{rt}>, rtc or
<{rp}> element, or if there is no more content in the parent element.
The <{rt}> element marks the ruby text component of a ruby annotation. When it is
the child of a <{ruby}> element or of an <{rtc}> element that is itself
the child of a <{ruby}> element, it doesn't represent anything itself, but its ancestor ruby
element uses it as part of determining what itrepresents.
An <{rt}> element that is not a child of a <{ruby}> element or of an
<{rtc}> element that is itself the child of a <{ruby}> element
represents the same thing as its children.
An <{rtc}> element's end tag may be omitted if the <{rtc}> element is
immediately followed by an rb or <{rtc}> element, or if there is no more
content in the parent element.
The <{rtc}> element marks a ruby text container for ruby text components
in a ruby annotation. When it is the child of a <{ruby}> element it doesn't represent anything itself, but its parent <{ruby}> element
uses it as part of determining what itrepresents.
An <{rtc}> element that is not a child of a <{ruby}> element
represents the same thing as its children.
When an <{rtc}> element is processed as part of the segmentation and
categorization of content for a <{ruby}> element, the following algorithm
defines how to process an <{rtc}> element:
Let root be the <{rtc}> element for which the algorithm is
being run.
Let index be 0.
Let annotations be an empty list of DOM ranges.
Let current automatic annotation nodes be an empty list of DOM nodes.
Let current automatic annotation range start be null.
Process an rtc child: If index is equal to or greater than the number of
child nodes in root, then run the steps to commit an automatic
annotation, return annotations, and abort these steps.
Let current child be the indexth node in root.
If current child is an <{rt}> element, then run these substeps:
Create a new DOM range whose start is the
boundary point (root,
index) and whose end is the boundary point (root, index plus
one), and append it at the end of annotations.
Increment index by one and jump to the step labelled process an rtc
child.
If current automatic annotation nodes is empty, set current automatic
annotation range start to the value of index.
Append current child at the end of current automatic annotation
nodes.
Increment index by one and jump to the step labelled process an rtc
child.
When the steps above say to commit an automatic annotation, it means to run the
following steps at that point in the algorithm:
If current automatic annotation nodes is empty, abort these steps.
If current automatic annotation nodes contains nodes that are not
{{Text}} nodes, or {{Text}} nodes that are not inter-element
white space, then create a new DOM range whose start is the boundary
point (root, current automatic annotation range start) and
whose end is the boundary point (root, index), and
append it at the end of annotations.
Let current automatic annotation nodes be an empty list of DOM nodes.
Let current automatic annotation range start be null.
An <{rp}> element's end tag may be omitted
if the <{rp}> element is immediately followed by an <{rb}>, <{rt}>,
rtc or <{rp}> element, or if there is no more content in the parent
element.
The <{rp}> element is used to provide fallback text to be shown by user agents that
don't support ruby annotations. One widespread convention is to provide parentheses around
the ruby text component of a ruby annotation.
The contents of the <{rp}> elements are typically not displayed by user agents
which do support ruby annotations
An <{rp}> element that is a child of a <{ruby}>
element represents nothing. An rp
element whose parent element is not a <{ruby}> element represents its
children.
The example shown previously, in which each ideograph in the text 漢字 is annotated with its phonetic reading, could be expanded
to use rp so that in legacy user agents the readings are in parentheses (please
note that white space has been introduced into this example in order to make it more
readable):
...
漢
字 (かんじ)
...
In conforming user agents the rendering would be as above, but in user agents that do not
support ruby, the rendering would be:
... 漢字 (かんじ) ...
When there are multiple annotations for a segment, <{rp}> elements can also be
placed between the annotations. Here is another copy of an earlier contrived example showing
some symbols with names given in English and French using double-sided annotations, but this
time with <{rp}> elements as well:
♥: Heart, .
☘: Shamrock, .
✶: Star, .
This would make the example render as follows in non-ruby-capable user agents:
The <{data}> element represents its contents, along with a
machine-readable form of those contents in the value
attribute.
The value attribute must be present. Its value
must be a representation of the element's contents in a machine-readable format.
When the value is a date or time, the more specific <{time}>
element should be used instead.
The element can be used to provide a machine-readable value for data processors,
including scripts running in the page, alongside a more human-readable value
that is rendered in a Web browser. Typical uses include microdata and microformats. [[microdata]][[microformats]]
The Instigator 2000
The value IDL attribute must
reflect the content attribute of the same name.
The <{time}> element represents its contents, along with a
machine-readable form of those contents in the datetime
attribute. The kind of content is limited to various kinds of dates, times, time-zone offsets, and
durations, as described below.
The datetime attribute may be present. If
present, its value must be a representation of the element's contents in a machine-readable
format.
A <{time}> element that does not have a datetime content attribute must not have any element
descendants.
The datetime value of a <{time}> element is the value of the element's
<{time/datetime}> content attribute, if it has one, otherwise the child text content of
the <{time}> element.
The datetime value of a <{time}> element must match one of the following
syntaxes.
Times with dates but without a time zone offset are useful for specifying events
that are observed at the same specific time in each time zone, throughout a day. For example,
the 2020 new year is celebrated at 2020-01-01 00:00 in each time zone, not at the same precise
moment across all time zones. For events that occur at the same time across all time zones, for
example a videoconference meeting, a valid global date and time string is likely
more useful.
For times without dates (or times referring to events that recur on multiple
dates), specifying the geographic location that controls the time is usually more useful than
specifying a time zone offset, because geographic locations change time zone offsets with
daylight savings time. In some cases, geographic locations even change time zone, e.g., when the
boundaries of those time zones are redrawn, as happened with Samoa at the end of 2011. There
exists a time zone database that describes the boundaries of time zones and what rules apply
within each such zone, known as the time zone database. [[TZDATABASE]]
Times with dates and a time zone offset are useful for specifying specific
events, or recurring virtual events where the time is not anchored to a specific geographic
location. For example, the precise time of an asteroid impact, or a particular meeting in a
series of meetings held at 1400 UTC every day, regardless of whether any particular part of the
world is observing daylight savings time or not. For events where the precise time varies by the
local time zone offset of a specific geographic location, a valid floating date and time
string combined with that geographic location is likely more useful.
Many of the preceding valid syntaxes describe "floating" date and/or time values
(they do not include a time-zone offset). Care is needed when
converting floating time values to or from global ("incremental") time values (e.g., JavaScript's
Date object). In many cases, an implicit time-of-day and time zone are used in the conversion and
may result in unexpected changes to the value of the date itself.
[[TIMEZONE]]
The machine-readable equivalent of the element's contents must be obtained from the
element's datetime value by using the following algorithm:
If the element's datetime value consists of only ASCII digits,
at least one of which is not U+0030 DIGIT ZERO (0), then the machine-readable equivalent is the
base-ten interpretation of those digits, representing a year; abort these steps.
The algorithms referenced above are intended to be designed such that for any
arbitrary string s, only one of the algorithms returns a value. A more
efficient approach might be to create a single algorithm that parses all these data types in one
pass; developing such an algorithm is left as an exercise to the reader.
The dateTime IDL attribute must
reflect the element's datetime content
attribute.
The <{time}> element can be used to encode dates, for example in microformats. The
following shows a hypothetical way of encoding an event using a variant on hCalendar that uses
the <{time}> element:
Here, a fictional RDFa vocabulary based on the Atom vocabulary is used with the
<{time}> element to mark up a blog post's publication date [[html-rdfa]].
Big tasks
Today, I went out and bought a bike for my kid.
In this example, another article's publication date is marked up using <{time}>, this
time using the schema.org vocabulary:
Small tasks
I put a bike bell on his bike.
In the following snippet, the <{time}> element is used to encode a date in the
ISO8601 format, for later processing by a script:
Our first date was .
In this second snippet, the value includes a time:
We stopped talking at .
A script loaded by the page (and thus privy to the page's internal convention of marking up
dates and times using the <{time}> element) could scan through the page and look at all
the <{time}> elements therein to create an index of dates and times.
For example, this element conveys the string "Friday" with the additional semantic that the
18th of November 2011 is the meaning that corresponds to "Friday":
Today is .
In this example, a specific time in the Pacific Standard Time timezone is specified:
Your next meeting is at .
The <{code}> element represents a fragment of computer code. This could
be an XML element name, a file name, a computer program, or any other string that a computer would
recognize.
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, can use the <{global/class}> attribute, e.g.,
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.
The code element represents a fragment of computer code.
When you call the activate() method on the robotSnowman object, the eyes glow.
The example below uses the begin keyword to indicate the start of a statement block. It is paired with an end keyword, which is followed by the . punctuation character (full stop) to indicate the end of the program.
The following example shows how a block of code could be marked up using the pre
and <{code}> elements.
var i: Integer;
begin
i := 1;
end.
A class is used in that example to indicate the language used.
The <{var}> element represents a variable. This could be an actual
variable in a mathematical expression or programming context, an identifier representing a
constant, a symbol identifying a physical quantity, a function parameter, or 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:
If there are n pipes leading to the ice cream factory then I expect at leastn flavors of ice cream to be available for purchase!
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}>.
Using Pythagoras' theorem to solve for the hypotenuse a of a triangle with sides b and c
Here, the equation describing mass-energy equivalence is used in a sentence, and the
<{var}> element is used to mark the variables and constants in that equation:
Then he turned to the blackboard and picked up the chalk. After a few moment's thought, he wrote E = mc2. The teacher looked pleased.
The <{samp}> element represents sample or quoted output from another
program or computing system.
See the pre and <{kbd}> elements for more details.
This element can be contrasted with the <{output}> element, which can be
used to provide immediate output in a Web application.
This example shows the <{samp}> element being used
inline:
The computer said Too much cheese in tray two but I didn't know what that meant.
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. There's also a few parts of the samp that are annotated with even more
detailed markup, to enable very precise styling. To achieve this, <{span}> elements are
used.
jdoe@mowmow:~$ssh demo.example.com
Last login: Tue Apr 12 09:10:17 2005 from mowmow.example.com on pts/1
Linux demo 2.6.10-grsec+gg3+e+fhs6b+nfs+gr0501+++p3+c4a+gr2b-reslog-v6.189 #1 SMP Tue Feb 1 11:22:36 PST 2005 i686 unknown
jdoe@demo:~$_
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.
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:
To make George eat an apple, press Shift+F3
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:
To make George eat an apple, select
File|Eat Apple...
Such precision isn't necessary; the following is equally fine:
To make George eat an apple, select File | Eat Apple...
The <{sub}> element represents a subscript, and the <{sup}> element represents a superscript.
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.
In certain languages, superscripts are part of the typographical conventions for some
abbreviations.
The most intelligent women are
Mlle de Beauvoir and
Mme Colette.
The <{sub}> element can be used inside a <{var}> element, for variables that
have subscripts.
Here, the <{sub}> element is used to represent the subscript that identifies the
variable in a family of variables:
The coordinate of the ith point is (xi, yi).
For example, the 10th point has coordinate (x10, y10).
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]]
The <{i}> element represents a span of text in an alternate voice or
mood, or otherwise offset from the normal prose in a manner indicating a different quality of
text, such as a taxonomic designation, a technical term, an idiomatic phrase from another
language, transliteration, a thought, or a ship name in Western texts.
Terms in languages different from the main text should be annotated with <{global/lang}> attributes (or, in XML, <{global/lang}> attributes in the XML namespace).
The examples below show uses of the <{i}> element:
The Felis silvestris catus is cute.
The term prose content is defined above.
There is a certain je ne sais quoi in the air.
In the following example, a dream sequence is marked up using
<{i}> elements.
Raymond tried to sleep.
The ship sailed away on Thursday, he dreamt. 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.
Finally one night he picked up the courage to speak with her—
Raymond woke with a start as the fire alarm rang out.
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.
The <{b}> element represents a span of text to which attention is being
drawn for utilitarian purposes without conveying any extra importance and with no implication of
an alternate voice or mood, such as key words in a document abstract, product names in a review,
actionable words in interactive text-driven software, or an article lede.
The following example shows a use of the <{b}> element to highlight key words without
marking them up as important:
The frobonitor and barbinator components are fried.
In the following example, objects in a text adventure are highlighted as being special by use
of the <{b}> element.
You enter a small room. Your sword glows brighter. A rat scurries past the corner wall.
Six abandoned kittens have found an unexpected new mother figure — a pet rabbit.
Veterinary nurse Melanie Humble took the three-week-old kittens to her Aberdeen home.
...
As with the <{i}> element, authors can use the <{global/class}>
attribute on the <{b}> element to identify why the element is being used, so that if the
style of a particular use is to be changed at a later date, the author doesn't have to go through
annotating each use.
The <{b}> element should be used as a last resort when no other element is more
appropriate. In particular, headings 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:
WARNING! Do not frob the barbinator!
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.
The <{u}> element represents a span of text with a non-textual annotation,
such as labeling a proper name in Chinese text, a surname, or text as being misspelt.
Underlining as a stylistic presentation is a convention in some cases:
Among others, Japanese, Hungarian and Chinese names are generally written with the family name first: Wu Xiaoqian.
and when the sun rises over the trees of fire, there are no other incediaris as powerful in this collection of dwelling
The see is full of fish
In most cases, another element is likely to be more appropriate: for marking stress emphasis,
the <{em}> element should be used; for marking key words or phrases either the <{b}> element or
the <{mark}> element should be used, depending on the context; for marking book titles, the
<{cite}> element should be used; for labeling text with explicit textual annotations, the
<{ruby}> element should be used; for technical terms, taxonomic designation, transliteration,
a thought, or for labeling ship names in Western texts, the <{i}> element should be used.
The default rendering of the <{u}> element in visual presentations clashes with the
conventional rendering of hyperlinks (underlining). Authors are encouraged to avoid using
the <{u}> element where it could be confused for a hyperlink.
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}> element can be used to bring attention to a
particular part of a quotation:
Consider the following quote:
Look around and you will find, no-one's really colour blind.
As we can tell from the spelling of the word, the person writing this quote is clearly not American.
(If the goal was to mark the element as misspelt, however, the <{u}> element,
possibly with a class, would be more appropriate.)
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:
I also have some kittens who are visiting me these days. They're really cute. I think they like my garden! Maybe I should adopt a kitten.
In the following snippet, a paragraph of text refers to a specific part of a code fragment.
The highlighted part below is where the error lies:
var i: Integer;
begin
i := 1.1;
end.
This is separate from syntax highlighting, for which span is more
appropriate. Combining both, one would get:
The highlighted part below is where the error lies:
vari: Integer;
begini := 1.1;
end.
This is another example showing the use of mark to highlight a part of quoted
text that was originally not emphasized. In this example, common typographic conventions have led
the author to explicitly style <{mark}> elements in quotes to render in italics.
She knew
Did you notice the subtle joke in the joke on panel 4?
I didn't want to believe. Of course on some level I realized it was a known-plaintext attack. But I couldn't admit it until I saw for myself.
(Emphasis mine.) I thought that was great. It's so pedantic, yet it explains everything neatly.
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.
Wormhole Physics Introduction
A wormhole in normal conditions can be held open for a maximum of just under 39 minutes. 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).
Momentum is preserved across the wormhole. Electromagnetic radiation can travel in both directions through a wormhole, but matter cannot.
When a wormhole is created, a vortex normally forms. Warning: The vortex caused by the wormhole opening will annihilate anything in its path. Vortexes can be avoided when using sufficiently advanced dialing technology.
An obstruction in a gate will prevent it from accepting a wormhole connection.
The <{bdi}> element represents a span of text that is to be isolated from
its surroundings for the purposes of bidirectional text formatting. [[!BIDI]]
The dir global attribute defaults to auto on this element
(it never inherits from the parent element like with other elements).
The <{bdi}> element is especially useful when embedding user-generated content with an unknown
directionality, or when incorporating spans of text that need to be rendered in the opposite
direction of the surrounding text.
In this example, usernames are shown along with the number of posts that the user has
submitted. If the <{bdi}> element were not used, the username of the Arabic user would end
up confusing the text (the bidirectional algorithm would put the colon and the number "3"
next to the word "User" rather than next to the word "posts").
User jcranmer: 12 posts.
User hober: 5 posts.
User إيان: 3 posts.
When using the <{bdi}> element, the username acts as expected.
The <{bdi}> element is a shorthand for <{span/dir}> with a value of auto, so the
<{global/dir}> attribute can be applied to another element to achieve the same result.
For example, the <{b}> element may be used to draw attention to part of the content:
If the <{bdi}> element were to be replaced by a <{b}> element, the username would confuse the bidirectional algorithm and the third bullet would end up saying "User 3 :", followed by the Arabic name (right-to-left), followed by "posts" and a period.
In this case the <{bdi}> and <{b}> elements could both be used, but where there is an
existing element available, the shortest way to achieve the same result is to apply the
<{global/dir}> attribute directly to the <{b}> element:
User jcranmer: 12 posts.
User hober: 5 posts.
User إيان: 3 posts.
When there is no existing element available, the <{bdi}> element can be used to achieve the
same effect.
The <{bdo}> element represents explicit text directionality formatting control for its
children. It allows authors to override the Unicode bidirectional algorithm while
explicitly specifying a direction override. [[!BIDI]]
Authors must specify the <{global/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. The auto value must not be specified.
The effect of using the <{bdo}> element is to completely disable the bidirectional
algorithm. This means that characters within the <{bdo}> element will be displayed exactly
as stored in memory and in the direction specified.
This is different than the <{bdi}> element, where the characters will be re-ordered and
re-arranged according to the directional algorithm. Use the <{bdo}> element only if you
specifically want to disable the bidirectional algorithm completely for that text.
The following example shows the difference in rendering between the <{bdi}> and <{bdo}> element.
שלום Majima! מה שלומך היום?
שלום Majima! מה שלומך היום?
שלום Majima! מה שלומך היום?
שלום Majima! מה שלומך היום?
שלום Majima! מה שלומך היום?
שלום Majima! מה שלומך היום?
In this example, you can see the Latin characters in the <{bdi}> element being rendered from
left-to-right, whereas the rest of the text being rendered right-to-left. This is because the
bidirectional algorithm recognizes Latin characters and automatically applies a left-to-right
rendering for just those characters.
In the <{bdo}> text, the bidirectional algorithm is disabled. So the text will be rendered
character by character in the direction specified, in a sequential order corresponding to
that of the characters in memory.
The <{span}> element doesn't mean anything on its own, but can be useful when used together with
the Global attributes, e.g., <{global/class}>, <{global/lang}>, or <{global/dir}>.
It represents its children.
In this example, a code fragment is marked up using
<{span}> elements and <{global/class}> attributes so that its keywords and
identifiers can be color-coded from CSS:
While line breaks are usually represented in visual media by physically moving
subsequent text to a new line, a style sheet or user agent would be equally justified in causing
line breaks to be rendered in a different manner, for instance as green dots, or as extra
spacing.
<{br}> elements must be used only for line breaks that are actually part of the
content, as in poems or addresses.
The following example is correct usage of the <{br}> element:
P. Sherman
42 Wallaby Way
Sydney
<{br}> elements must not be used for separating thematic groups in a paragraph.
The following examples are non-conforming, as they abuse the <{br}> element:
If a paragraph consists of nothing but a single <{br}> element, it
represents a placeholder blank line (e.g., as in a template). Such blank lines must not be used for
presentation purposes.
Any content inside <{br}> elements must not be considered part of the surrounding
text.
The <{wbr}> element represents a line break opportunity.
In the following example, someone is quoted as saying something which, for effect, is written
as one long word. However, to ensure that the text can be wrapped in a readable fashion, the
individual words in the quote are separated using a <{wbr}> element.
So then he pointed at the tiger and screamed "thereisnowayyouareevergoingtocatchme"!
Here, especially long lines of code in a program listing have suggested wrapping points given
using <{wbr}> elements.