This element includes the global attributes.
<dt>
download
HTML5
</dt>
/
and
\
will be converted to underscores, preventing specific path hints), but you should consider that most file systems have limitations with regard to what punctuation is supported in file names, and browsers are likely to adjust file names accordingly.
Note:
- Can be used with blob:
URLs and data:
URLs, to make it easy for users to download content that is generated programmatically using JavaScript (e.g. a picture created using an online drawing Web app).
- If the HTTP header Content-Disposition:
is present and gives a different filename than this attribute, the HTTP header has priority over this attribute.
- If this attribute is present and Content-Disposition:
is set to inline
, Firefox gives priority to Content-Disposition
, like for the filename case, while Chrome gives priority to the download
attribute.
- This attribute is only honored for links to resources with the same-origin.
href
</dt>
href
attribute indicates the link target, either a URL or a URL fragment. A URL fragment is a name preceded by a hash mark (#), which specifies an internal target location (an
ID) within the current document. URLs are not restricted to Web (HTTP)-based documents. URLs might use any protocol supported by the browser. For example,
file
,
ftp
, and
mailto
work in most user agents.
Note: You can use the special fragment "top" to create a link back to the top of the page; for example <a href="#top">Return to top</a>
. This behavior is specified by HTML5.
hreflang
</dt>
href
attribute is present.
media
HTML5
</dt>
print
, screen
, aural
, braille
, ... HTML 5 extended this to any kind of media queries, which are a superset of the allowed values of HTML 4.
- Browsers not supporting the CSS3 Media Queries won't necessarily recognize the adequate link; do not forget to set fallback links, the restricted set of media queries defined in HTML 4.
ping
HTML5
</dt>
rel
</dt>
target
</dt>
_self
: Load the response into the same HTML4 frame (or HTML5 browsing context) as the current one. This value is the default if the attribute is not specified.
- _blank
: Load the response into a new unnamed HTML4 window or HTML5 browsing context.
- _parent
: Load the response into the HTML4 frameset parent of the current frame or HTML5 parent browsing context of the current one. If there is no parent, this option behaves the same way as _self
.
- _top
: In HTML4: Load the response into the full, original window, canceling all other frames. In HTML5: Load the response into the top-level browsing context (that is, the browsing context that is an ancestor of the current one, and has no parent). If there is no parent, this option behaves the same way as _self
.
Use this attribute only if the
href attribute is present.
type
</dt>
href
attribute is present.
charset
Obsolete since HTML5
</dt>
coords
HTML 4 only,
Obsolete since HTML5
</dt>
name
HTML 4 only,
Obsolete since HTML5
</dt>
rev
HTML 4 only,
Obsolete since HTML5
</dt>
shape
HTML 4 only,
Obsolete since HTML5
</dt>
circle
,
default
,
polygon
, and
rect
. The format of the
coords attribute depends on the value of shape. For
circle
, the value is
x,y,r
where
x
and
y
are the pixel coordinates for the center of the circle and
r
is the radius value in pixels. For
rect
, the
coords attribute should be
x,y,w,h
. The
x,y
values define the upper-left-hand corner of the rectangle, while
w
and
h
define the width and height respectively. A value of
polygon
for
shape requires
x1,y1,x2,y2,...
values for
coords. Each of the
x,y
pairs defines a point in the polygon, with successive points being joined by straight lines and the last point joined to the first. The value
default
for shape requires that the entire enclosed area, typically an image, be used.
Note: It is advisable to use the
usemap
attribute for the
<img>
element and the associated
<map>
element to define hotspots instead of the
shape
attribute.
datafld
Support | Gecko | Presto | WebKit | Trident |
Not implemented | Not implemented | Not implemented | IE4, IE5, IE6, IE7 (Removed in IE8) | |
Normative document | Microsoft's Data Binding: dataFld Property (MSDN) |
datasrc
Support | Gecko | Presto | WebKit | Trident |
Not implemented | Not implemented | Not implemented | IE4, IE5, IE6, IE7 (Removed in IE8) | |
Normative document | Microsoft's Data Binding: dataSrc Property (MSDN) |
methods
urn
The HTML Acronym Element (<acronym>)
allows authors to clearly indicate a sequence of characters that compose an acronym or abbreviation for a word.
The HTML Acronym Element (<acronym>)
allows authors to clearly indicate a sequence of characters that compose an acronym or abbreviation for a word.
Usage note: This element has been removed in HTML5 and shouldn't be used anymore. Instead web developers should use the <abbr>
element.
The HTML Address
Element (<address>) should be used by authors to supply contact information for its nearest <article>
or <body>
ancestor; in the latter case, it applies to the whole document.
The HTML Address
Element (<address>) should be used by authors to supply contact information for its nearest <article>
or <body>
ancestor; in the latter case, it applies to the whole document.
Usage note:
<p>
element rather than the <address> element.<time>
element).<footer>
element of the current section, if any.The HTML Applet Element (<applet>
) identifies the inclusion of a Java applet.
The HTML Applet Element (<applet>
) identifies the inclusion of a Java applet.
Usage note: This element has been removed in HTML5 and shouldn't be used anymore. Instead web developers should use the more generic <object>
element.
The HTML <area>
element defines a hot-spot region on an image, and optionally associates it with a hypertext link.
The HTML <area>
element defines a hot-spot region on an image, and optionally associates it with a hypertext link. This element is used only within a <map>
element.
The HTML Article
Element (<article>) represents a self-contained composition in a document, page, application, or site, which is intended to be independently distributable or reusable, e.g., in syndication.
The HTML Article
Element (<article>) represents a self-contained composition in a document, page, application, or site, which is intended to be independently distributable or reusable, e.g., in syndication. This could be a forum post, a magazine or newspaper article, a blog entry, or any other independent item of content. Each <article>
should be identified, typically by including a heading (h1-h6 element) as a child of the <article>
element.
Usage notes:
<article>
element is nested, the inner element represents an article related to the outer element. For example, the comments of a blog post can be <article>
elements nested in the <article>
representing the blog post.<article>
element can be provided through the <address>
element, but it doesn't apply to nested <article>
elements.<article>
element can be described using the datetime
attribute of a <time>
element. Note that the pubdate
attribute of <time>
is no longer a part of the W3C HTML 5 standard.The HTML <audio>
element is used to embed sound content in documents.
The HTML <audio>
element is used to embed sound content in documents. It may contain several audio sources, represented using the src
attribute or the <source>
element; the browser will choose the most suitable one.
Fallback content for browser not supporting the <audio>
element can be added too.
You can use the Web Audio API to directly generate and manipulate audio streams from JavaScript code. See Web Audio API for details.
The HTML <b>
Element represents a span of text stylistically different from normal text, without conveying any special importance or relevance.
The HTML <b>
Element represents a span of text stylistically different from normal text, without conveying any special importance or relevance. It is typically used for keywords in a summary, product names in a review, or other spans of text whose typical presentation would be boldfaced. Another example of its use is to mark the lead sentence of each paragraph of an article.
Usage notes:
<b>
element with the <strong>
, <em>
, or <mark>
elements. The <strong>
element represents text of certain importance, <em>
puts some emphasis on the text and the <mark>
element represents text of certain relevance. The <b>
element doesn't convey such special semantic information; use it only when no others fit.
- Similarly, do not mark titles and headings using the <b>
element. For this purpose, use the <h1>
to <h6>
tags. Further, stylesheets can change the default style of these elements, with the result that they are not necessarily displayed in bold.
- It is a good practice to use the class attribute on the <b>
in order to convey additional semantic information (for example <b class="lead">
for the first sentence in a paragraph). This eases the development of several stylings of a web document, without the need to change its HTML code.
- Historically, the <b>
element was meant to make text boldface. Styling information has been deprecated since HTML4, so the meaning of the <b>
element has been changed.
- If there is no semantic purpose on using the <b> element, using css property font-weight with bold value would be a better choice for making text bold.
The HTML Base Element (<base>) specifies the base URL to use for all relative URLs contained within a document.
The HTML Base Element (<base>) specifies the base URL to use for all relative URLs contained within a document. There can be only one <base> element in a document.
The base URL of a document can be queried from a script using document.baseURI
.
Usage Note: If multiple
<base>
elements are specified, only the first
href and first
target value are used; all others are ignored.
The HTML basefont element (<basefont>
) establishes a default font size for a document.
The HTML basefont element (<basefont>
) establishes a default font size for a document. Font size then can be varied relative to the base font size using the <font>
element.
Usage note:
Do not use this element! Though once (imprecisely) normalized in HTML 3.2, it wasn't supported in all major browsers. Further, browsers, and even successive versions of browsers, never implemented it in the same way: practically, using it has always brought indeterminate results.
The <basefont>
element was deprecated in the standard at the same time as all elements related to styling only. Starting with HTML 4, HTML does not convey styling information anymore (outside the <style>
element or the style attribute of each element). In HTML5, this element has been removed completely. For any new web development, styling should be written using CSS only.
The former behavior of the <font>
element can be achieved, and even better controlled using the font
, font-family
, font-size
, font-size-adjust
, font-stretch
, font-style
, font-variant
, font-weight
, @font-face
properties.
The HTML Big Element (<big>
) makes the text font size one size bigger (for example, from small to medium, or from large to x-large) up to the browser's maximum font size.
The HTML Big Element (<big>
) makes the text font size one size bigger (for example, from small to medium, or from large to x-large) up to the browser's maximum font size.
Usage note: As it was purely presentational, this element has been removed in HTML5 and shouldn't be used anymore. Instead web developers should use CSS properties.
The HTML Body Element (<body>) represents the content of an HTML document.
The HTML Body Element (<body>) represents the content of an HTML document. There can be only one <body>
element in a document.
The HTML <br>
Element (or HTML Line Break Element) produces a line break in text (carriage-return).
The HTML <button>
Element represents a clickable button.
The HTML <button>
Element represents a clickable button.
This element includes the global attributes.
This element includes the global attributes.
<dt>
height
</dt>
moz-opaque
</dt>
width
</dt>
The HTML <caption>
Element (or HTML Table Caption Element) represents the title of a table.
The HTML <caption>
Element (or HTML Table Caption Element) represents the title of a table. Though it is always the first descendant of a <table>
, its styling, using CSS, may place it elsewhere, relative to the table.
Usage note: When the
<table>
element that is the parent of this
<caption>
is the only descendant of a
<figure>
element, use the
<figcaption>
element instead.
The HTML Center Element (<center>
) is a block-level element that can contain paragraphs and other block-level and inline elements.
The HTML Center Element (<center>
) is a block-level element that can contain paragraphs and other block-level and inline elements. The entire content of this element is centered horizontally within its containing element (typically, the <body>
).
This tag has been deprecated in HTML 4 (and XHTML 1) in favor of the CSS text-align
property, which can be applied to the <div>
element or to an individual <p>
. For centering blocks, use other CSS properties like margin-left
and margin-right
and set them to auto
(or set margin
to 0 auto
).
The HTML Code Element (<code>) represents a fragment of computer code.
The HTML Code Element (<code>) represents a fragment of computer code. By default, it is displayed in the browser's default monospace font.
The HTML Table Column Element (<col>) defines a column within a table and is used for defining common semantics on all common cells.
The HTML Table Column Element (<col>) defines a column within a table and is used for defining common semantics on all common cells. It is generally found within a <colgroup>
element.
The HTML Table Column Group Element (<colgroup>) defines a group of columns within a table.
The HTML Table Column Group Element (<colgroup>) defines a group of columns within a table.
The HTML <content>
element is used inside of Shadow DOM as an insertion point.
The HTML <content>
element is used inside of Shadow DOM as an insertion point. It is not intended to be used in ordinary HTML. It is used with Web Components.
The HTML Datalist Element (<datalist>) contains a set of <option>
elements that represent the values available for other controls.
The HTML Datalist Element (<datalist>) contains a set of <option>
elements that represent the values available for other controls.
The HTML Description Element (<dd>) indicates the description of a term in a description list (<dl>
) element.
The HTML Deleted Text Element (<del>) represents a range of text that has been deleted from a document.
The HTML Deleted Text Element (<del>) represents a range of text that has been deleted from a document. This element is often (but need not be) rendered with strike-through text.
The HTML Details Element (<details>
) is used as a disclosure widget from which the user can retrieve additional information.
The HTML Details Element (<details>
) is used as a disclosure widget from which the user can retrieve additional information.
The HTML <dialog>
element represents a dialog box or other interactive component, such as an inspector or window.
The HTML <dialog>
element represents a dialog box or other interactive component, such as an inspector or window. <form>
elements can be integrated within a dialog by specifying them with the attribute method="dialog"
. When such a form is submitted, the dialog is closed with a returnValue
attribute set to the value
of the submit button used.
The ::backdrop
CSS pseudo-element can be used to style behind a <dialog>
element, for example to dim inaccessible content whilst a modal dialog is active.
The HTML directory element (<dir>
) represents a directory, namely a collection of filenames.
The HTML <div>
element (or HTML Document Division Element) is the generic container for flow content, which does not inherently represent anything.
The HTML <div>
element (or HTML Document Division Element) is the generic container for flow content, which does not inherently represent anything. It can be used to group elements for styling purposes (using the class or id attributes), or because they share attribute values, such as lang. It should be used only when no other semantic element (such as <article>
or <nav>
) is appropriate.
The HTML <dl>
Element (or HTML Description List Element) encloses a list of pairs of terms and descriptions.
The HTML <dl>
Element (or HTML Description List Element) encloses a list of pairs of terms and descriptions. Common uses for this element are to implement a glossary or to display metadata (a list of key-value pairs).
Prior to HTML5, <dl> was known as a Definition List.
The HTML <dt>
element (or HTML Definition Term Element) identifies a term in a definition list.
The HTML <dt>
element (or HTML Definition Term Element) identifies a term in a definition list. This element can occur only as a child element of a <dl>
. It is usually followed by a <dd>
element; however, multiple <dt>
elements in a row indicate several terms that are all defined by the immediate next <dd>
element.
The HTML <element>
element is used to define new custom DOM elements.
The HTML <element>
element is used to define new custom DOM elements.
The HTML Emphasis Element (<em>) marks text that has stress emphasis.
The HTML Emphasis Element (<em>) marks text that has stress emphasis. The <em>
element can be nested, with each level of nesting indicating a greater degree of emphasis.
Usage Note: Typically this element is displayed in italic type. However, it should not be used simply to apply italic styling; use the CSS styling for that purpose. Use the
<cite>
element to mark the title of a work (book, play, song, etc.); it is also typically styled with italic type, but carries different meaning. Use the
<strong>
element to mark text that has greater importance than surrounding text.
The HTML <embed>
Element represents an integration point for an external application or interactive content (in other words, a plug-in).
The HTML <embed>
Element represents an integration point for an external application or interactive content (in other words, a plug-in).
Note: This topic documents only the element that is defined as part of HTML5. It does not address earlier, non-standardized implementation of the element.
This element includes the global attributes.
This element includes the global attributes.
<dt>
disabled
HTML5
</dt>
<legend>
element, are disabled, i.e., not editable. They won't receive any browsing events, like mouse clicks or focus-related ones. Often browsers display such controls as gray.
form
HTML5
<form>
element its related to. Its default value is the
id of the nearest
<form>
element it is a descendant of.
name
HTML5
<legend>
element that is a child of this field set.
The HTML <figcaption>
Element represents a caption or a legend associated with a figure or an illustration described by the rest of the data of the <figure>
element which is its immediate ancestor which means <figcaption>
can be the first or last element inside a <figure>
block. Also, the HTML Figcaption Element is optional; if not provided, then the parent figure element will have no caption.
The HTML <figcaption>
Element represents a caption or a legend associated with a figure or an illustration described by the rest of the data of the <figure>
element which is its immediate ancestor which means <figcaption>
can be the first or last element inside a <figure>
block. Also, the HTML Figcaption Element is optional; if not provided, then the parent figure element will have no caption.
The HTML <figure>
Element represents self-contained content, frequently with a caption (<figcaption>
),
and is typically referenced as a single unit.
The HTML <figure>
Element represents self-contained content, frequently with a caption (<figcaption>
),
and is typically referenced as a single unit. While it is related to the main flow, its position is independent of the main flow. Usually this is an image, an illustration, a diagram, a code snippet, or a schema that is referenced in the main text, but that can be moved to another page or to an appendix without affecting the main flow.
Usage notes:
<figure>
element by inserting a <figcaption>
inside it (as the first or the last child).The HTML Footer Element (<footer>) represents a footer for its nearest sectioning content or sectioning root element.
The HTML Footer Element (<footer>) represents a footer for its nearest sectioning content or sectioning root element. A footer typically contains information about the author of the section, copyright data or links to related documents.
Usage notes:
The HTML <form>
element represents a document section that contains interactive controls to submit information to a web server.
<frame>
is an HTML element which defines a particular area in which another HTML document can be displayed.
<frame>
is an HTML element which defines a particular area in which another HTML document can be displayed. A frame should be used within a <frameset>
.
Using the <frame>
element is not encouraged because of certain disadvantages such as performance problems and lack of accessibility for users with screen readers. Instead of the <frame>
element, <iframe>
may be preferred.
<frameset>
is an HTML element which is used to contain <frame>
elements.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least.
Heading elements implement six levels of document headings, <h1>
is the most important and <h6>
is the least. A heading element briefly describes the topic of the section it introduces. Heading information may be used by user agents, for example, to construct a table of contents for a document automatically.
The HTML Head Element (<head>) provides general information (metadata) about the document, including its title and links to or definitions of scripts and style sheets
The HTML Head Element (<head>) provides general information (metadata) about the document, including its title and links to or definitions of scripts and style sheets
The HTML <header>
Element represents a group of introductory or navigational aids.
The HTML <header>
Element represents a group of introductory or navigational aids. It may contain some heading elements but also other elements like a logo, wrapped section's header, a search form, and so on.
Usage note:
<header>
element is not sectioning content and therefore doesn't introduce a new section in the outline.The HTML <hgroup>
Element (HTML Headings Group Element) represents the heading of a section.
The HTML <hgroup>
Element (HTML Headings Group Element) represents the heading of a section. It defines a single title that participates in the outline of the document as the heading of the implicit or explicit section that it belongs to.
Its text for the outline algorithm is the text of the first HTML Heading Element of highest rank (i.e., the first <h1>
, <h2>
, <h3>
, <h4>
, <h5>
or <h6>
with the smallest number among its descendants) and the rank is the rank of this very same HTML Heading Element.
Therefore this element groups several headings, contributing only the main one to the outline of the document. It allows associating secondary titles, like subheadings, alternative titles, or even taglines, with the main heading, without polluting the outline of the document.
The HTML <hr>
element represents a thematic break between paragraph-level elements (for example, a change of scene in a story, or a shift of topic with a section).
The HTML <hr>
element represents a thematic break between paragraph-level elements (for example, a change of scene in a story, or a shift of topic with a section). In previous versions of HTML, it represented a horizontal rule. It may still be displayed as a horizontal rule in visual browsers, but is now defined in semantic terms, rather than presentational terms.
The HTML Root Element (<html>
) represents the root of an HTML document.
The HTML Root Element (<html>
) represents the root of an HTML document. All other elements must be descendants of this element.
The HTML <i>
Element represents a range of text that is set off from the normal text for some reason, for example, technical terms, foreign language phrases, or fictional character thoughts.
The HTML <i>
Element represents a range of text that is set off from the normal text for some reason, for example, technical terms, foreign language phrases, or fictional character thoughts. It is typically displayed in italic type.
The HTML Inline Frame Element (<iframe>
) represents a nested browsing context, effectively embedding another HTML page into the current page.
The HTML Inline Frame Element (<iframe>
) represents a nested browsing context, effectively embedding another HTML page into the current page. In HTML 4.01, a document may contain a head
and a body
or a head
and a frame-set
, but not both a body
and a frame-set
. However, an <iframe>
can be used within a normal document body. Each browsing context has its own session history and active document. The browsing context that contains the embedded content is called the parent browsing context. The top-level browsing context (which has no parent) is typically the browser window.
The HTML Image Element (<img>) represents an image of the document.
The HTML Image Element (<img>) represents an image of the document.
Usage note:
Browsers do not always display the image referenced by the element. This is the case for non-graphical browsers (including those used by people with vision impairments), if the user chooses not to display images, or if the browser is unable to display the image because it is invalid or an unsupported type. In these cases, the browser may replace the image with the text defined in this element's alt attribute.
The HTML <input>
element is used to create interactive controls for web-based forms in order to accept data from the user.
The HTML <input>
element is used to create interactive controls for web-based forms in order to accept data from the user. How an <input>
works varies considerably depending on the value of its type
attribute.
The HTML <ins>
Element (or HTML Inserted Text) HTML represents a range of text that has been added to a document.
The HTML <ins>
Element (or HTML Inserted Text) HTML represents a range of text that has been added to a document.
<isindex>
is an HTML element which is used for putting a text field in the document for querying document.
<isindex>
is an HTML element which is used for putting a text field in the document for querying document. <isindex>
is intented to use inside of <head>
element by W3C, however browsers provide support wherever it is used in the document.
This element deprecated in HTML 4.01. Because, it is not a good idea to use <isindex>
for any purpose. Same effect can be created with a HTML form in a modern way.
This element includes the global attributes.
<dt>
autofocus
</dt>
autofocus
attribute, which is a Boolean.
challenge
</dt>
disabled
</dt>
form
</dt>
id
of a
<form>
element in the same document. If this attribute is not specified, this element must be a descendant of a
<form>
element. This attribute enables you to place
<keygen>
elements anywhere within a document, not just as descendants of their form elements.
keytype
</dt>
RSA
.
name
</dt>
keytype
parameter is used to specify what type of key is to be generated.This element includes the global attributes.
<dt>
autofocus
</dt>
autofocus
attribute, which is a Boolean.
challenge
</dt>
disabled
</dt>
form
</dt>
id
of a
<form>
element in the same document. If this attribute is not specified, this element must be a descendant of a
<form>
element. This attribute enables you to place
<keygen>
elements anywhere within a document, not just as descendants of their form elements.
keytype
</dt>
RSA
.
name
</dt>
keytype
parameter is used to specify what type of key is to be generated. Valid values are "RSA
", which is the default, "DSA
" and "EC
". The name
and challenge
attributes are required in all cases. The keytype
attribute is optional for RSA key generation and required for DSA and EC key generation. The keyparams
attribute is required for DSA and EC key generation and ignored for RSA key generation. PQG
is a synonym for keyparams
. That is, you may specify keyparams="pqg-params"
or pqg="pqg-params"
.
For RSA keys, the keyparams
parameter is not used (ignored if present). The user may be given a choice of RSA key strengths. Currently, the user is given a choice between "high" strength (2048 bits) and "medium" strength (1024 bits).
For DSA keys, the keyparams
parameter specifies the DSA PQG parameters which are to be used in the keygen process. The value of the pqg
parameter is the the BASE64 encoded, DER encoded Dss-Parms as specified in IETF RFC 3279. The user may be given a choice of DSA key sizes, allowing the user to choose one of the sizes defined in the DSA standard.
For EC keys, the keyparams
parameter specifies the name of the elliptic curve on which the key will be generated. It is normally a string from the table in nsKeygenHandler.cpp. (Note that only a subset of the curves named there may actually be supported in any particular browser.) If the keyparams
parameter string is not a recognized curve name string, then a curve is chosen according to the user's chosen key strength (low, medium, high), using the curve named "secp384r1
" for high, and the curve named "secp256r1
" for medium keys. (Note: choice of the number of key strengths, default values for each strength, and the UI by which the user is offered a choice, are outside of the scope of this specification.)
The <keygen>
element is only valid within an HTML form. It will cause some sort of selection to be presented to the user for selecting key size. The UI for the selection may be a menu, radio buttons, or possibly something else. The browser presents several possible key strengths. Currently, two strengths are offered, high and medium. If the user's browser is configured to support cryptographic hardware (e.g. "smart cards") the user may also be given a choice of where to generate the key, i.e., in a smart card or in software and stored on disk.
When the submit button is pressed, a key pair of the selected size is generated. The private key is encrypted and stored in the local key database.
PublicKeyAndChallenge ::= SEQUENCE {
spki SubjectPublicKeyInfo,
challenge IA5STRING
}
SignedPublicKeyAndChallenge ::= SEQUENCE {
publicKeyAndChallenge PublicKeyAndChallenge,
signatureAlgorithm AlgorithmIdentifier,
signature BIT STRING
}
The public key and challenge string are DER encoded as PublicKeyAndChallenge
, and then digitally signed with the private key to produce a SignedPublicKeyAndChallenge
. The SignedPublicKeyAndChallenge
is Base64 encoded, and the ASCII data is finally submitted to the server as the value of a form name/value pair, where the name is name as specified by the name
attribute of the keygen
element. If no challenge string is provided, then it will be encoded as an IA5STRING
of length zero.
Here is an example form submission as it would be delivered to a CGI program by the HTTP server:
commonname=John+Doe&[email protected]&org=Foobar+Computing+Corp.&
orgunit=Bureau+of+Bureaucracy&locality=Anytown&state=California&country=US&
key=MIHFMHEwXDANBgkqhkiG9w0BAQEFAANLADBIAkEAnX0TILJrOMUue%2BPtwBRE6XfV%0AWtKQbsshxk5ZhcUwcwyvcnIq9b82QhJdoACdD34rqfCAIND46fXKQUnb0mvKzQID%0AAQABFhFNb3ppbGxhSXNNeUZyaWVuZDANBgkqhkiG9w0BAQQFAANBAAKv2Eex2n%2FS%0Ar%2F7iJNroWlSzSMtTiQTEB%2BADWHGj9u1xrUrOilq%2Fo2cuQxIfZcNZkYAkWP4DubqW%0Ai0%2F%2FrgBvmco%3D
The HTML Label Element (<label>
) represents a caption for an item in a user interface.
The HTML Label Element (<label>
) represents a caption for an item in a user interface. It can be associated with a control either by placing the control element inside the <label>
element, or by using the for
attribute. Such a control is called the labeled control of the label element.
This element only includes the global attributes.
This element only includes the global attributes.
The HTML List Item Element (<li>
) is used to represent an item in a list.
The HTML List Item Element (<li>
) is used to represent an item in a list. It must be contained in a parent element: an ordered list (<ol>
), an unordered list (<ul>
), or a menu (<menu>
). In menus and unordered lists, list items are usually displayed using bullet points. In ordered lists, they are usually displayed with an ascending counter on the left, such as a number or letter.
The HTML Link Element (<link>) specifies relationships between the current document and an external resource.
The HTML Link Element (<link>) specifies relationships between the current document and an external resource. Possible uses for this element include defining a relational framework for navigation. This Element is most used to link to style sheets. <link href="style.css" rel="stylesheet">
The HTML Listing Element (<listing>
) renders text between the start and end tags without interpreting the HTML in between and using a monospaced font.
The HTML Listing Element (<listing>
) renders text between the start and end tags without interpreting the HTML in between and using a monospaced font. The HTML 2 standard recommended that lines shouldn't be broken when not greater than 132 characters.
Note: Do not use this element.
<pre>
element, which will interpret the internal HTML!<pre>
element or if semantically adequate the <code>
element, eventually escaping the HTML '<
' and '>
' so that they don't get interpreted.<div>
element, by applying an adequate CSS style using monospace
as the generic-font value in a font-family
property.The HTML Main Element (<main>) can be used as a container for the dominant contents of the document.
The HTML Main Element (<main>) can be used as a container for the dominant contents of the document. The main content area consists of content that is directly related to, or expands upon the central topic of a section or the central functionality of an application. This content should be unique to the document, excluding any content that is repeated across a set of documents such as sidebars, navigation links, copyright information, site logos, and search forms (unless, of course, the document's main function is as a search form). Unlike <article>
and <section>
, this element does not contribute to the document outline.
This element includes the global attributes.
This element includes the global attributes.
<dt>
name
</dt>
This element includes the global attributes.
This element includes the global attributes.
<dt>
label
</dt>
<menu>
in the
context menu state.
type
</dt>
context
: The context menu state, which represents a group of commands activated through another element. This might be through the menu
attribute of a <button>
, or an element with a contextmenu
attribute. When nesting <menu>
elements directly within one another, this is the missing value default if the parent is already in this state.
- list
: The list menu state, which represents a series of commands for user interaction. This is the missing value default, except where the parent element is a <menu>
in the context menu state.
The HTML <menuitem>
element represents a command that a user is able to invoke through a popup menu.
The HTML <menuitem>
element represents a command that a user is able to invoke through a popup menu. This includes context menus, as well as menus that might be attached to a menu button.
A command can either be defined explicitly, with a textual label and optional icon to describe its appearance, or alternatively as an indirect command whose behavior is defined by a separate element. Commands can also optionally include a checkbox or be grouped to share radio buttons. (Menu items for indirect commands gain checkboxes or radio buttons when defined against elements <input type="checkbox">
and <input type="radio">
.)
The HTML Meta Element (<meta>) represents any metadata information that cannot be represented by one of the other HTML meta-related elements (<base>
, <link>
, <script>
, <style>
or <title>
).
The HTML Meta Element (<meta>) represents any metadata information that cannot be represented by one of the other HTML meta-related elements (<base>
, <link>
, <script>
, <style>
or <title>
).
Depending on the attributes set, the kind of metadata can be one of the following:
name
is set, it is document-level metadata, applying to the whole page.http-equiv
is set, it is a pragma directive, i.e. information normally given by the web server about how the web page should be served.charset
is set, it is a charset declaration, i.e. the charset used for the serialized form of the webpage. HTML5itemprop
is set, it is user-defined metadata, transparent for the user-agent as the semantics of the metadata is user-specific. Living Standard Unimplemented
The HTML <meter>
Element represents either a scalar value within a known range or a fractional value.
The HTML <meter>
Element represents either a scalar value within a known range or a fractional value.
Usage note: Unless the
value attribute is between 0 and 1 (inclusive), the
min attribute and
max attribute should define the range so that the
value attribute's value is within it.
The HTML Navigation Element (<nav>
) represents a section of a page that links to other pages or to parts within the page: a section with navigation links.
The HTML Navigation Element (<nav>
) represents a section of a page that links to other pages or to parts within the page: a section with navigation links.
Usage notes:
<nav>
element, which is intended only for major block of navigation links; typically the <footer>
element often has a list of links that don't need to be in a <nav>
element.<nav>
elements, for example, one for site navigation and one for intra-page navigation.The HTML <noscript>
Element defines a section of html to be inserted if a script type on the page is unsupported or if scripting is currently turned off in the browser.
The HTML <noscript>
Element defines a section of html to be inserted if a script type on the page is unsupported or if scripting is currently turned off in the browser.
The HTML Embedded Object Element (<object>) represents an external resource, which can be treated as an image, a nested browsing context, or a resource to be handled by a plugin.
The HTML Embedded Object Element (<object>) represents an external resource, which can be treated as an image, a nested browsing context, or a resource to be handled by a plugin.
The HTML <ol>
Element (or HTML Ordered List Element) represents an ordered list of items.
The HTML <ol>
Element (or HTML Ordered List Element) represents an ordered list of items. Typically, ordered-list items are displayed with a preceding numbering, which can be of any form, like numerals, letters or Romans numerals or even simple bullets. This numbered style is not defined in the HTML description of the page, but in its associated CSS, using the list-style-type
property.
There is no limitation to the depth and overlap of lists defined with the <ol>
and <ul>
elements.
Usage note: The
<ol>
and
<ul>
both represent a list of items. They differ in the way that, with the
<ol>
element, the order is meaningful. As a rule of thumb to determine which one to use, try changing the order of the list items; if the meaning is changed, the
<ol>
element should be used, else the
<ul>
is adequate.
In a Web form, the HTML <optgroup>
element creates a grouping of options within a <select>
element.
Note: Optgroup elements may not be nested.
In a Web form, the HTML <optgroup>
element creates a grouping of options within a <select>
element.
Note: Optgroup elements may not be nested.
This element includes the global attributes.
This element includes the global attributes.
<dt>
disabled
</dt>
<optgroup>
element.
label
label
attribute isn't defined, its value is that of the element text content.
Usage note: the
label
attribute is designed to contain a short label typically used in a hierarchical menu. The
value
attribute describes a longer label designed to be used near a radio button, for example.
selected
<option>
element is the descendant of a
<select>
element whose
multiple
attribute is not set, only one single
<option>
of this
<select>
element may have the
selected attribute.
value
The HTML <output>
element represents the result of a calculation or user action.
The HTML <output>
element represents the result of a calculation or user action.
The HTML <p>
element (or HTML Paragraph Element) represents a paragraph of text. Paragraphs are block-level elements.
The HTML <p>
element (or HTML Paragraph Element) represents a paragraph of text. Paragraphs are block-level elements.
The HTML <param>
Element (or HTML Parameter Element) defines parameters for <object>
.
The HTML <param>
Element (or HTML Parameter Element) defines parameters for <object>
.
The HTML Plaintext Element (<plaintext>
) renders everything following the start tag as raw text, without interpreting any HTML.
The HTML Plaintext Element (<plaintext>
) renders everything following the start tag as raw text, without interpreting any HTML. There is no closing tag, since everything after it is considered raw text.
Note: Do not use this element.
<pre>
element, which still interprets HTML within, even though that's not what you probably want.<plaintext>
element is the first element on the page (other than any non-displayed elements), do not use HTML at all. Configure your server to send your page with the text/plain
MIME-type.<pre>
element or, if semantically adequate, the <code>
element. Be sure to escape any "<", ">" and "&" characters, to avoid inadvertently interpreting content as HTML.<div>
element by applying an adequate CSS style using monospace
as the generic-font value in a font-family
property.The HTML Preformatted Text (<pre>) represents preformatted text.
The HTML Preformatted Text (<pre>) represents preformatted text. Text within this element is typically displayed in a non-proportional font exactly as it is laid out in the file. Whitespaces inside this element are displayed as typed.
The HTML <progress>
Element is used to view the completion progress of a task.
The HTML <progress>
Element is used to view the completion progress of a task. While the specifics of how it's displayed is left up to the browser developer, it's typically displayed as a progress bar. Javascript can be used to manipulate the value of progress bar.
The HTML Script Element (<script>
) is used to embed or reference an executable script within an HTML or XHTML document.
The HTML Script Element (<script>
) is used to embed or reference an executable script within an HTML or XHTML document.
Scripts without async
or defer
attributes, as well as inline scripts, are fetched and executed immediately, before the browser continues to parse the page.
The HTML Section Element (<section>
) represents a generic section of a document, i.e., a thematic grouping of content, typically with a heading.
The HTML Section Element (<section>
) represents a generic section of a document, i.e., a thematic grouping of content, typically with a heading. Each <section>
should be identified, typically by including a heading (<h1>
-<h6>
element) as a child of the <section>
element.
Usage notes :
<section>
element, use an <article>
element instead.<section>
element as a generic container; this is what <div>
is for, especially when the sectioning is only for styling purposes. A rule of thumb is that a section should logically appear in the outline of a document.The HTML select (<select>
) element represents a control that presents a menu of options.
The HTML select (<select>
) element represents a control that presents a menu of options. The options within the menu are represented by
elements, which can be grouped by <option>
elements. Options can be pre-selected for the user.
<optgroup>
The HTML <shadow>
element is used as a shadow DOM insertion point.
The HTML <shadow>
element is used as a shadow DOM insertion point. You might use it if you have created multiple shadow roots under a shadow host. It is not useful in ordinary HTML. It is used with Web Components.
The HTML Small Element (<small>) makes the text font size one size smaller (for example, from large to medium, or from small to x-small) down to the browser's minimum font size. In HTML5, this element is repurposed to represent side-comments and small print, including copyright and legal text, independent of its styled presentation.
The HTML Small Element (<small>) makes the text font size one size smaller (for example, from large to medium, or from small to x-small) down to the browser's minimum font size. In HTML5, this element is repurposed to represent side-comments and small print, including copyright and legal text, independent of its styled presentation.
The HTML <source>
element is used to specify multiple media resources for <picture>
, <audio>
and <video>
elements.
The HTML <source>
element is used to specify multiple media resources for <picture>
, <audio>
and <video>
elements. It is an empty element. It is commonly used to serve the same media in multiple formats supported by different browsers.
<spacer>
is an HTML element which is used for inserting white spaces to web pages.
<spacer>
is an HTML element which is used for inserting white spaces to web pages. It was created by NetScape for achieving same effect as a single-pixel layout GIF image, which was something web designers used to use to add white spaces to web pages, without actually using a GIF. However <spacer>
is not supported by any major browser and same effects can be created with various CSS rules. In Mozilla applications, support for this element was removed in Gecko 2.0. Therefore usage of <spacer>
is unnecessary.
The HTML <span>
element is a generic inline container for phrasing content, which does not inherently represent anything.
The HTML <span>
element is a generic inline container for phrasing content, which does not inherently represent anything. It can be used to group elements for styling purposes (using the class
or id
attributes), or because they share attribute values, such as lang
. It should be used only when no other semantic element is appropriate. <span>
is very much like a <div>
element, but <div>
is a block-level element whereas a <span>
is an inline element.
The HTML Strikethrough Element (<strike>
) renders text with a strikethrough, or a line through it.
The HTML Strikethrough Element (<strike>
) renders text with a strikethrough, or a line through it.
Usage Note: As with all purely styling elements,
<strike>
has been deprecated in HTML 4 and XHTML 1, and obsoleted in HTML5. If semantically appropriate, i.e., if it represents
deleted content, use the
<del>
instead; in all other cases use a
<span>
element and style it with the
CSS
text-decoration
property, with the
line-through
value.
The HTML Strong Element (<strong>
) gives text strong importance, and is typically displayed in bold.
The HTML Strong Element (<strong>
) gives text strong importance, and is typically displayed in bold.
The HTML Style Element (<style>) contains style information for a document, or part of a document.
The HTML Style Element (<style>) contains style information for a document, or part of a document. By default, the style instructions written inside that element are expected to be CSS.
The HTML summary element (<summary>
) is used as a summary, caption, or legend for the content of a <details>
element.
The HTML summary element (<summary>
) is used as a summary, caption, or legend for the content of a <details>
element.
Note: If the
<summary>
element is omitted, the heading "details" will be used.
The HTML Table Element (<table>
) represents data in two dimensions or more.
The HTML Table Element (<table>
) represents data in two dimensions or more.
Note: Prior to the creation of
CSS, HTML
<table>
elements were often used as a method for page layout. This usage has been discouraged since HTML 4, and the
<table>
element
should
not be used for layout purposes. However, HTML emails are an exception, where tables are still commonly used for layout purposes.
The HTML Table Body Element (<tbody>) defines one or more <tr>
element data-rows to be the body of its parent <table>
element (as long as no <tr> elements are immediate children of that table element.) In conjunction with a preceding <thead>
and/or <tfoot>
element, <tbody> provides additional semantic information for devices such as printers and displays. Of the parent table's child elements, <tbody> represents the content which, when longer than a page, will most likely differ for each page printed; while the content of <thead>
and <tfoot>
will be the same or similar for each page printed. For displays, <tbody> will enable separate scrolling of the <thead>
, <tfoot>
, and <caption>
elements of the same parent <table>
element. Note that unlike the <thead>, <tfoot>, and <caption> elements however, multiple <tbody> elements are permitted (if consecutive), allowing the data-rows in long tables to be divided into different sections, each separately formatted as needed.
The HTML Table Body Element (<tbody>) defines one or more <tr>
element data-rows to be the body of its parent <table>
element (as long as no <tr> elements are immediate children of that table element.) In conjunction with a preceding <thead>
and/or <tfoot>
element, <tbody> provides additional semantic information for devices such as printers and displays. Of the parent table's child elements, <tbody> represents the content which, when longer than a page, will most likely differ for each page printed; while the content of <thead>
and <tfoot>
will be the same or similar for each page printed. For displays, <tbody> will enable separate scrolling of the <thead>
, <tfoot>
, and <caption>
elements of the same parent <table>
element. Note that unlike the <thead>, <tfoot>, and <caption> elements however, multiple <tbody> elements are permitted (if consecutive), allowing the data-rows in long tables to be divided into different sections, each separately formatted as needed.
The Table cell HTML element (<td>
) defines a cell of a table that contains data.
The Table cell HTML element (<td>
) defines a cell of a table that contains data. It participates in the table model.
The HTML template element <template>
is a mechanism for holding client-side content that is not to be rendered when a page is loaded but may subsequently be instantiated during runtime using JavaScript.
Think of a template as a content fragment that is being stored for subsequent use in the document.
The HTML template element <template>
is a mechanism for holding client-side content that is not to be rendered when a page is loaded but may subsequently be instantiated during runtime using JavaScript.
Think of a template as a content fragment that is being stored for subsequent use in the document. While the parser does process the contents of the <template>
element while loading the page, it does so only to ensure that those contents are valid; the element's contents are not rendered, however.
The HTML <textarea>
element represents a multi-line plain-text editing control.
The HTML <textarea>
element represents a multi-line plain-text editing control.
The HTML Table Foot Element (<tfoot>
) defines a set of rows summarizing the columns of the table.
The HTML Table Foot Element (<tfoot>
) defines a set of rows summarizing the columns of the table.
The HTML Table Header Cell Element (<th>
) defines a cell that is a header for a group of cells of a table.
The HTML Table Head Element (<thead>
) defines a set of rows defining the head of the columns of the table.
The HTML Table Head Element (<thead>
) defines a set of rows defining the head of the columns of the table.
The HTML Title Element (<title>) defines the title of the document, shown in a browser's title bar or on the page's tab.
The HTML Title Element (<title>) defines the title of the document, shown in a browser's title bar or on the page's tab. It can only contain text and any contained tags are not interpreted.
The HTML Table Row Element (<tr>
) defines a row of cells in a table.
The HTML Teletype Text Element (<tt>
) produces an inline element displayed in the browser's default monotype font.
The HTML Teletype Text Element (<tt>
) produces an inline element displayed in the browser's default monotype font. This element was intended to style text as it would display on a fixed width display, such as a teletype. It probably is more common to display fixed width type using the <code>
element.
This element is obsolete. Use a more appropriate element, such as
<code>
or
<span>
with
CSS, instead.
The HTML unordered list element (<ul>
) represents an unordered list of items, namely a collection of items that do not have a numerical ordering, and their order in the list is meaningless.
The HTML unordered list element (<ul>
) represents an unordered list of items, namely a collection of items that do not have a numerical ordering, and their order in the list is meaningless. Typically, unordered-list items are displayed with a bullet, which can be of several forms, like a dot, a circle or a squared. The bullet style is not defined in the HTML description of the page, but in its associated CSS, using the list-style-type
property.
There is no limitation to the depth and imbrication of lists defined with the <ol>
and <ul>
elements.
Usage note: The
<ol>
and
<ul>
elements both represent a list of items. They differ in that, with the
<ol>
element, the order is meaningful. As a rule of thumb to determine which one to use, try changing the order of the list items; if the meaning is changed, the
<ol>
element should be used, otherwise you can use
<ul>
.
The HTML <video>
element is used to embed video content.
The HTML <video>
element is used to embed video content. It may contain several video sources, represented using the src
attribute or the <source>
element; the browser will choose the most suitable one.
For a list of supported formats, see Media formats supported by the audio and video elements.
The HTML Example Element (<xmp>
) renders text between the start and end tags without interpreting the HTML in between and using a monospaced font.
The HTML Example Element (<xmp>
) renders text between the start and end tags without interpreting the HTML in between and using a monospaced font. The HTML2 specification recommended that it should be rendered wide enough to allow 80 characters per line.
Note: Do not use this element.
<pre>
element or, if semantically adequate, the <code>
element instead. Note that you will need to escape the '<
' character as '<
' to make sure it is not interpreted as markup.monospace
as the generic-font value for the font-family
property.
This element includes the global attributes. <dt>
download
HTML5 </dt>/
and\
will be converted to underscores, preventing specific path hints), but you should consider that most file systems have limitations with regard to what punctuation is supported in file names, and browsers are likely to adjust file names accordingly. Note: - Can be used withblob:
URLs anddata:
URLs, to make it easy for users to download content that is generated programmatically using JavaScript (e.g. a picture created using an online drawing Web app). - If the HTTP headerContent-Disposition:
is present and gives a different filename than this attribute, the HTTP header has priority over this attribute. - If this attribute is present andContent-Disposition:
is set toinline
, Firefox gives priority toContent-Disposition
, like for the filename case, while Chrome gives priority to thedownload
attribute. - This attribute is only honored for links to resources with the same-origin.href
</dt>href
attribute indicates the link target, either a URL or a URL fragment. A URL fragment is a name preceded by a hash mark (#), which specifies an internal target location (an ID) within the current document. URLs are not restricted to Web (HTTP)-based documents. URLs might use any protocol supported by the browser. For example,file
,ftp
, andmailto
work in most user agents. Note: You can use the special fragment "top" to create a link back to the top of the page; for example<a href="#top">Return to top</a>
. This behavior is specified by HTML5.hreflang
</dt>href
attribute is present.media
HTML5 </dt>print
,screen
,aural
,braille
, ... HTML 5 extended this to any kind of media queries, which are a superset of the allowed values of HTML 4. - Browsers not supporting the CSS3 Media Queries won't necessarily recognize the adequate link; do not forget to set fallback links, the restricted set of media queries defined in HTML 4.ping
HTML5 </dt>rel
</dt>target
</dt>_self
: Load the response into the same HTML4 frame (or HTML5 browsing context) as the current one. This value is the default if the attribute is not specified. -_blank
: Load the response into a new unnamed HTML4 window or HTML5 browsing context. -_parent
: Load the response into the HTML4 frameset parent of the current frame or HTML5 parent browsing context of the current one. If there is no parent, this option behaves the same way as_self
. -_top
: In HTML4: Load the response into the full, original window, canceling all other frames. In HTML5: Load the response into the top-level browsing context (that is, the browsing context that is an ancestor of the current one, and has no parent). If there is no parent, this option behaves the same way as_self
. Use this attribute only if the href attribute is present.type
</dt>href
attribute is present.charset
Obsolete since HTML5 </dt>coords
HTML 4 only, Obsolete since HTML5 </dt>name
HTML 4 only, Obsolete since HTML5 </dt>rev
HTML 4 only, Obsolete since HTML5 </dt>shape
HTML 4 only, Obsolete since HTML5 </dt>circle
,default
,polygon
, andrect
. The format of the coords attribute depends on the value of shape. Forcircle
, the value isx,y,r
wherex
andy
are the pixel coordinates for the center of the circle andr
is the radius value in pixels. Forrect
, the coords attribute should bex,y,w,h
. Thex,y
values define the upper-left-hand corner of the rectangle, whilew
andh
define the width and height respectively. A value ofpolygon
for shape requiresx1,y1,x2,y2,...
values for coords. Each of thex,y
pairs defines a point in the polygon, with successive points being joined by straight lines and the last point joined to the first. The valuedefault
for shape requires that the entire enclosed area, typically an image, be used. Note: It is advisable to use theusemap
attribute for the<img>
element and the associated<map>
element to define hotspots instead of theshape
attribute.datafld
datasrc
methods
urn