HTML5 elements, attributes, and APIs support in Opera Presto 2.10

W3C references
W3C HTML5 Working Draft
W3C HTML5 differences from HTML 4
Opera articles
Accessible HTML5 Video with JavaScripted captions
An HTML5 <audio> radio player
Building a custom HTML5 video player with CSS3 and jQuery
Blob Sallad - canvas tag and JavaScript physics simulation experiment
Creating an HTML5 canvas painting application
Creating pseudo 3D games with HTML5 canvas and raycasting
Everything you need to know about HTML5 video and audio
HTML5 canvas - the basics
Introduction to HTML5 video
Opera supports the WebM video format
Rich HTML editing in the browser: part 1
Rich HTML editing in the browser: part 2
SVG or Canvas? Choosing between the two
On this page...
New HTML5 elements support
New HTML5 attributes support
Global attributes
Changed elements support
Changed attributes support
New HTML5 APIs support

Overview

HTML5 is still a working draft and not a W3C recommendation. Opera Presto is providing support for various elements, attributes, and values as the draft matures towards recommendation status. This document points out which new HTML5 elements, attributes, values, and APIs are supported, partially supported, or not supported by Opera Presto. Changes, additions, and removals may occur from time to time. HTML5 is a work in progress and respectively, Opera considers its implementations for HTML5 experimental until its specification has stabilized.

New HTML5 elements support

The following table defines which new HTML5 elements are supported by Opera Presto. Each <element> is given a short description/example and is hyperlinked to its place within the W3C HTML5 Working Draft.

Element name Description Support
<section> Represents a generic document or application section. It can be used together with the h1, h2, h3, h4, h5, and h6 elements to indicate the document structure. Yes
<article> Represents an independent piece of content of a document, such as a blog entry or newspaper article. Yes
<aside> Represents a piece of content that is only slightly related to the rest of the page. Yes
<hgroup> Represents the header of a section. Yes
<header> Represents a group of introductory or navigational aids. Yes
<footer> Represents a footer for a section and can contain information about the author, copyright information, etc. Yes
<nav> Represents a section of the document intended for navigation. Yes
<figure> Can be used to associate a caption together with some embedded content, such as a graphic or video: 
<figure>
  <video src="ogg"></video>
    <figcaption>Example</figcaption>
</figure>
Yes
<figcaption> Provides the caption for the <figure> element's contents. Yes
<video> Represents a video or movie. It is a media element whose media data is ostensibly video data, possibly with associated audio data.
  • The preload attribute is supported; for your reference, autobuffer was changed to preload in the specification.
  • The buffered attribute is supported.
  • The seekable attribute is supported.
  • The played attribute always returns empty TimeRanges.objects.
    • playbackRate and defaultPlaybackRate do not affect playback speed or direction.
 Yes
<audio> Represents a sound or audio stream. It is a media element whose media data is ostensibly audio data.
  • Note: Opera supports the HTML5 media elements with the following exceptions:
    • preload attribute is not supported; for your reference, autobuffer was changed to preload in the specification.
    • buffered, seekable and played IDL attributes always return empty TimeRanges objects.
    • playbackRate and defaultPlaybackRate do not affect playback speed or direction.
 Partial
<source> Allows authors to specify multiple media resources for media elements. It does not represent anything on its own. Yes
<embed> It is is used for plug-in content. It represents an integration point for an external (typically non-HTML) applications or interactive content. Yes
<mark> Represents a run of text in one document marked or highlighted for reference purposes, due to its relevance in another context. Yes
<progress> Represents a completion of a task such as downloading, or when performing a series of expensive operations. Yes
<meter> Represents a scalar measurement within a known range, or a fractional value; for example:
  • disk usage
  • the relevance of a query result
  • the fraction of a voting population to have selected a particular candidate
 Yes
<time> Represents either a time on a 24 hour clock, or a precise date in the proleptic Gregorian calendar, optionally with a time and a time zone. It provides an API for accessing the date/time as a Date object. Opera's support:
  • Extends support only to the element and the API; bindings are not applied to alter its layout.
  • Extends <input type="datetime"> to support timezones other than "Z".
 Yes
<ruby> 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. No
<rt> Marks the ruby text component of a ruby annotation. No
<rp> Can be used to provide parentheses around a ruby text component of a ruby annotation, to be shown by user agents that do not support ruby annotations. No
<wbr> Represents a line-break opportunity where phrasing content is expected. For 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. No
<canvas> Represents a resolution-dependent bitmap canvas, which can be used for rendering graphs, game graphics, or other visual images on the fly. Yes
<command> Represents a command that the user can invoke. No
<details> Represents additional information or controls which the user can obtain on demand. No
<summary> Represents a summary, caption, or legend for the rest of the contents of the summary element's parent details element, if any. No
<datalist> Represents a set of <option> elements that represent predefined options for other controls. The contents of the element represents fallback content for legacy user agents, intermixed with <option> elements that represent the predefined options. In the rendering, the <datalist> element represents nothing and it, along with its children, should be hidden. The <datalist> element together with the new list attribute for input can be used to make comboboxes: 
<input list="browsers">
  <datalist id="browsers">
    <option value="browser A">
    <option value="browser B">
    <option value="browser C">
    <option value="browser D">
  </datalist>
Yes
<keygen> Represents a key pair generator control. When the control's form is submitted, the private key is stored in the local keystore, and the public key is packaged and sent to the server. 
<form action="processkey.cgi" method="post"
 enctype="multipart/formdata">
  <p><keygen name="key"></p>
  <p>input type=submit value="Submit key..."></p>
</form>
Yes
<output> Represents some type of output, as from a calculation done through scripting. Yes
<input> The <input> element type attribute now has the following new values. Yes

New HTML5 attributes support

Attribute name Description Support
indeterminate The indeterminate attribute of the <input> element is used to change the appearance of checkbox controls. Yes
preload The preload attribute of the <video> element is intended to provide a hint to the user agent about what the author thinks will lead to the best user experience. For your reference, the autobuffer attribute was changed to preload in the specification. No
media The <a> and <area> elements now have a media attribute for consistency with the <link> element. It is purely advisory. Yes
ping The <a> and <area> elements have a new attribute called ping that specifies a space-separated list of URLs which have to be pinged when a hyperlink is followed. Currently user tracking is mostly done through redirects. This attribute allows the user agent to inform users which URLs are going to be pinged as well as giving privacy-conscious users a way to turn it off. No
hreflang The <area> element, for consistency with the <a> and <link> elements, now also has the hreflang attribute. Yes
rel The <area> element, for consistency with the <a> and <link> elements, now also has the rel attribute. Yes
target The <base> element can now have a target attribute as well, mainly for consistency with the <a> element. (This is already widely supported.) Also, the target attribute for the <a> and <area> elements is no longer deprecated, as it is useful in Web applications, e.g. in conjunction with <iframe>. Yes
value The value attribute for the <li> element is no longer deprecated as it is not presentational. Yes
start The start attribute for the <ol> element is no longer deprecated as it is not presentational. Yes
charset The <meta> element now has a charset attribute. This was already widely supported and provides a way to specify the character encoding for the document. Yes
autofocus A new autofocus attribute can be specified on the <input> (except when the type attribute is hidden), <select>, <textarea>, and <button> elements. It provides a declarative way to focus a form control during page load. Using this feature should enhance the user experience, as the user can turn it off if he does not like it. Yes
placeholder A new placeholder attribute can be specified on the <input> and <textarea> elements. It represents a short hint (a word or short phrase) intended to aid the user with data entry. A hint could be a sample value or a brief description of the expected format. The placeholder attribute should not be used as an alternative to a label. Yes
form The new form attribute for <input>, <output>, <select>, <textarea>, <button>, and <fieldset> elements allows for controls to be associated with a form. I.e., these elements can now be placed anywhere on a page, not just as descendants of the <form> element. Yes
required The new required attribute applies to <input> (except when the type attribute is hidden, image or some button type such as submit) and <textarea>. It indicates that the user has to fill in a value in order to submit the form. Yes
disabled The <fieldset> element now allows the disabled attribute which disables all its contents when specified. Yes
autocomplete This is a new attribute of the <input> element which specifies constraint. It is an enumerated attribute that has two states:
  • The on keyword maps to the on state
  • The off keyword maps to the off state
 No
min This is a new attribute of the <input> element which specifies constraint. It indicates the allowed range of values for the element. If the element has a min attribute, and the result of applying the algorithm to convert a string to a number to the value of the min attribute is a number, then that number is the element's minimum. Yes
max This is a new attribute of the <input> element which specifies constraint. It indicates the allowed range of values for the element. If the element has a max attribute, and the result of applying the algorithm to convert a string to a number to the value of the max attribute is a number, then that number is the element's maximum. Yes
multiple This is a new attribute of the <input> element which specifies constraint. It is a boolean attribute that indicates whether the user is to be allowed to specify more than one value. Yes
pattern This is a new attribute of the <input> element which specifies constraint. It specifies a regular expression against which the control's value is to be checked. If specified, the attribute's value must match the JavaScript Pattern production. Yes
step This is a new attribute of the <input> element which specifies constraint. It indicates the granularity that is expected (and required) of the value, by limiting the allowed values. Yes
list This is a new attribute of the <input> element which specifies constraint. It can be used together with the <datalist> and <select> elements. It identifies an element that lists predefined options suggested to the user. If present, its value must be the ID of a <datalist> element in the same document. Yes
novalidate This content attribute of the <form> element is a boolean attribute that can be used to disable form validation submission (i.e., the form can always be submitted). If present, it indicates that the form is not to be validated during submission. Yes
formaction This is a new attribute of the <input> and <button> elements. If present, it overrides the action attribute on the form element. If specified, it must have a value that is a valid URL. The action of an element is the value of the element's formaction attribute. Yes
formenctype This is a new attribute of the <input> and <button> elements. If present, it overrides the action attribute on the <form> element. The formenctype content attribute is also an enumerated attribute with the following keywords and states:
  • The "application/x-www-form-urlencoded" keyword and corresponding state
  • The "multipart/form-data" keyword and corresponding state
  • The "text/plain" keyword and corresponding state
 Yes
formmethod The formmethod content attribute is an enumerated attribute with the following keywords and states:
  • The keyword GET, mapping to the state GET, indicating the HTTP GET method
  • The keyword POST, mapping to the state POST, indicating the HTTP POST method
  • The keyword PUT, mapping to the state PUT, indicating the HTTP PUT method
  • The keyword DELETE, mapping to the state DELETE, indicating the HTTP DELETE method
 Yes
formnovalidate The formnovalidate content attribute is a boolean attribute. If present, it indicates that the form is not to be validated during submission. Yes
formtarget The formtarget content attribute, if specified, must have a value that is a valid browsing context name or keyword. Yes
type This is a new attribute of the <menu> element. It allows the element to transform into a menu as found in typical user interfaces, and provides for context menus in conjunction with the global contextmenu attribute. The type attribute controls the data type (and associated control) of the element. It is an enumerated attribute indicating the kind of menu being declared. The attribute has three states:
  • The context keyword maps to the context menu state, in which the element is declaring a context menu.
  • The toolbar keyword maps to the tool bar state, in which the element is declaring a tool bar.
  • The attribute may also be omitted. The missing value default is the list state, which indicates that the element is merely a list of commands that is neither declaring a context menu nor defining a tool bar.
 No
label This is a new attribute of the <menu> element, and gives the label of the menu. It is used by user agents to display nested menus in the UI. For example, a context menu containing another menu would use the nested menu's label attribute for the submenu's menu label. No
scoped The scoped attribute is a boolean attribute. If set, it indicates that the styles are intended just for the subtree rooted at the style element's parent element, as opposed to the whole Document. If it is present, then the user agent must apply the specified style information only to the <style> element's parent element (if any), and that element's child nodes. Otherwise, the specified styles must, if applied, be applied to the entire document. No
async This is a new attribute of the <script> element that influences script loading and execution. It is a boolean attribute that indicates how the script should be executed. There are three possible modes that can be selected:
  • If the async attribute is present, then the script will be executed asynchronously, as soon as it is available.
  • If the async attribute is not present but the defer attribute (not supported by Opera) is present , then the script is executed when the page has finished parsing.
  • If neither attribute is present, then the script is fetched and executed immediately, before the user agent continues parsing the page.
 No
manifest The <html> element has a new attribute called manifest that points to an application cache manifest used in conjunction with the API for offline Web applications. If the attribute is present, the attribute's value must be a valid URL. The manifest attribute only has an effect during the early stages of document load. Changing the attribute dynamically thus has no effect (and thus, no DOM API is provided for this attribute). Yes
sizes The <link> element has a new attribute called sizes. It can be used in conjunction with the icon relationship (set through the rel attribute) to indicate the size of the referenced icon for visual media. No
reversed The <ol> element has a new attribute called reversed. It is a boolean attribute. If present, it indicates that the list is a descending list (..., 3, 2, 1). If the attribute is omitted, the list is an ascending list (1, 2, 3, ...). No
sandbox The sandbox attribute of the <iframe> element enables a set of extra restrictions on any content hosted by the iframe. Its value must be an unordered set of unique space-separated tokens. The allowed values are:
  • allow-same-origin
  • allow-forms
  • allow-scripts
When the sandbox attribute is set:
  • The content is treated as being from a unique origin
  • Forms and scripts are disabled
  • Links are prevented from targeting other browsing contexts
  • Plugins are disabled
 No
seamless The seamless attribute is a boolean attribute of the <iframe> element. When specified, it indicates that the <iframe> element's browsing context is to be rendered in a manner that makes it appear to be part of the containing document (seamlessly included in the parent document). No
srcdoc The srcdoc attribute of the <iframe> element gives the content of the page that the nested browsing context is to contain. It is expected to be used together with the sandbox and seamless attributes. No

Global Attributes

HTML 4 attributes now specified as global in HTML5

Several attributes from HTML 4 now apply to all elements. These are called global attributes.

Attribute name Description Support
class Every HTML element may have a class attribute specified. The attribute, if specified, must have a value that is an unordered set of unique space-separated tokens representing the various classes that the element belongs to. The classes that an HTML element has assigned to it consists of all the classes returned when the value of the class attribute is split on spaces. Yes
dir The dir attribute specifies the element's text directionality (left-to-right, or right-to-left). The attribute is an enumerated attribute with the keyword ltr ((left-to-right) mapping to the state ltr, and the keyword rtl (right-to-left) mapping to the state rtl. The attribute has no defaults. Yes
id The id attribute represents its element's unique identifier. The value must be unique in the element's home subtree and must contain at least one character. The value must not contain any space characters. Yes
lang The lang attribute (in no namespace) specifies the primary language for the element's contents and for any of the element's attributes that contain text. Its value must be a valid BCP 47 language code, or the empty string. Yes
style All HTML elements may have the style content attribute set. If specified, the attribute must contain only a list of zero or more semicolon-separated (;) CSS declarations. In user agents that support CSS, the attribute's value must be parsed when the attribute is added or has its value changed, with its value treated as the body (the part inside the curly brackets) of a declaration block in a rule whose selector matches just the element on which the attribute is set. All URLs in the value must be resolved relative to the element when the attribute is parsed. For the purposes of the CSS cascade, the attribute must be considered to be a style attribute at the author level. Documents that use style attributes on any of their elements must still be comprehensible and usable if those attributes were removed. Yes
tabindex The tabindex content attribute specifies :
  • If the element is focusable
  • If it can be reached using sequential focus navigation
  • The relative order of the element for the purposes of sequential focus navigation
The name "tab index" comes from the common use of the tab key to navigate through the focusable elements. The term "tabbing" refers to moving forward through the focusable elements that can be reached using sequential focus navigation. If it is specified, it must have a value that is a valid integer, and it must be parsed using the rules for parsing integers. 		Yes
title The title attribute represents advisory information:
  • For an element, such as would be appropriate for a tooltip
  • On a link, this could be the title or a description of the target resource
  • On an image, it could be the image credit or a description of the image
  • On a paragraph, it could be a footnote or commentary on the text
  • On a citation, it could be further information about the source
  • etc.
The value is text. 		Yes

New global attributes in HTML5

Attribute name Description Support
contenteditable The contenteditable attribute is an enumerated attribute whose keywords are the empty string, true, and false. The empty string and the true keyword map to the true state. The false keyword maps to the false state. In addition, there is a third state, the inherit state, which is the missing value default (and the invalid value default).
  • The true state indicates that the element is editable.
  • The inherit state indicates that the element is editable if its parent is.
  • The false state indicates that the element is not editable.
 Yes
contextmenu The contextmenu attribute gives the element's context menu. The value must be the ID of a menu element in the DOM. If the node that would be obtained by the invoking the getElementById() method using the attribute's value as the only argument is null or not a menu element, then the element has no assigned context menu. Otherwise, the element's assigned context menu is the element so identified. No
data-* A custom data attribute is an attribute in no namespace whose name starts with the string "data-", has at least one character after the hyphen, is XML-compatible, and contains no characters in the range U+0041 .. U+005A (LATIN CAPITAL LETTER A .. LATIN CAPITAL LETTER Z). Custom data attributes are intended to store custom data private to the page or application, for which there are no more appropriate attributes or elements. These attributes are not intended for use by software that is independent of the site that uses the attributes. Every HTML element may have any number of custom data attributes specified, with any value. They refer to the DOM Dataset API. Yes
draggable All HTML elements may have the draggable content attribute set. It is an enumerated attribute, and has three states:
  • The first state is true and it has the keyword true. The true state means the element is draggable.
  • The second state is false and it has the keyword false. The false state means that it is not draggable.
  • The third state is auto; it has no keywords but it is the missing value default. The auto state uses the default behavior of the user agent.
 No
hidden All HTML elements may have the hidden content attribute set. The hidden attribute is a boolean attribute. When specified on an element, it indicates that the element is not yet, or is no longer, relevant. User agents should not render elements that have the hidden attribute specified. Yes
role An implementing host language will provide an attribute with the following characteristics:
  • The attribute name MUST be role
  • The attribute value MUST allow a token list as the value
  • The appearance of the name literal of any concrete WAI-ARIA role as one of these substrings MUST NOT in and of itself make the attribute value illegal in the host-language syntax
  • The first name literal of a non-abstract WAI-ARIA role in the list of tokens in the role attribute defines the role according to which the user agent MUST process the element. User Agent processing for roles
 Yes
aria-* The WAI-ARIA Attributes Module declares the WAI-ARIA attributes as a module that can be included in a modularlized DTD. Note the WAI-ARIA attributes are in no namespace, and the attribute name begins with "aria-" to reduce the likelihood of collision with existing attributes. Yes
spellcheck The spellcheck attribute is an enumerated attribute whose keywords are the empty string, true and false. The empty string and the true keyword map to the true state. The false keyword maps to the false state. Please note that the "default" state has been removed.
  • The true state indicates that the element is to have its spelling and grammar checked.
  • The false state indicates that the element is not to be checked.
 Yes

New event handler DOM attributes

HTML5 also makes all event handler attributes from HTML4 that take the form onevent-name global attributes, and adds several new event handler attributes for new events it defines, such as the message event which is used by the cross-document messaging API.

Attribute name Description Support
focusin A user agent must dispatch this event when an event target is about to receive focus. This event type must be dispatched before the element is given focus. The event target must be the element which is about to receive focus. This event type is similar to focus, but is dispatched before focus is shifted, and does bubble. Yes
focusout A user agent must dispatch this event when an event target is about to lose focus. This event type must be dispatched before the element loses focus. The event target must be the element which is about to lose focus. This event type is similar to blur, but is dispatched before focus is shifted, and does bubble. Yes
onhashchange The HTML5 onhashchange event must be invoked whenever a hashchange event is targeted at or bubbles through the object. It must be supported by Window objects, as DOM attributes on the Window object, and with corresponding content attributes and DOM attributes exposed on the <body> element. The hashchange event is fired asynchronously when navigating to a session history entry whose URL differs from that of the previous one only in the fragment identifier. Yes

Changed elements support

These HTML 4 elements have slightly modified meanings in HTML5 to better reflect how they are used on the Web or to make them more useful.

Element name Description Support
<a> The <a> element without an href attribute now represents a "placeholder link". It can also contain flow content rather than being restricted to phrase content. Yes
<address> The <address> element is now scoped by the new concept of sectioning. It represents the contact information for its nearest article or body element ancestor. If that is the body element, then the contact information applies to the document as a whole. Yes
<b> The <b> element represents a span of text to be stylistically offset from the normal prose without conveying any extra importance, such as key words in a document abstract, product names in a review, or other spans of text whose typical typographic presentation is boldened. Yes
<cite> The <cite> element now solely represents the title of a work (e.g. a book, a paper, an essay, a poem, a score, a song, a script, a film, a TV show, a game, a sculpture, a painting, a theatre production, a play, an opera, a musical, an exhibition, a legal case report, etc). Specifically the example in HTML4 where it is used to mark up the name of a person is no longer considered conforming. Yes
<hr> The <hr> element represents a paragraph-level thematic break, e.g. a scene change in a story, or a transition to another topic within a section of a reference book. Yes
<i> The <i> element represents a span of text in an alternate voice or mood, or otherwise offset from the normal prose, such as a taxonomic designation, a technical term, an idiomatic phrase from another language, a thought, a ship name, or some other prose whose typical typographic presentation is italicized. Yes
<label> For the <label> element the browser should no longer move focus from the label to the control unless such behavior is standard for the underlying platform user interface. Yes
<menu> The <menu> element represents a list of commands and is redefined to be useful for toolbars and context menus.
  • Please note that as described in the "New HTML5 attributes support" topic:
    • The label attribute is not yet supported.
    • The type attribute is not yet supported.
 Partial
<small> The <small> element now represents small print (for side comments and legal print). Yes
<strong> The <strong> element now represents importance rather than strong emphasis. Yes
<head> The <head> element no longer allows the object element as child. Yes

Changed attributes support

The following attributes are allowed, but authors are strongly encouraged to not use them and instead use an alternative solution.

Attribute name Description Support
border The border attribute on <img>: is required to have the value "0" when present. Authors can use CSS instead. Yes
language The language attribute on <script>: is required to have the value "JavaScript" (case-insensitive) when present and cannot conflict with the type attribute. Authors can simply omit it, as it has no useful function. Yes
name The name attribute on <a>: authors can use the id attribute instead. Yes
summary The summary attribute on <table>: the HTML5 draft defines several alternative solutions. No

New HTML5 APIs support

HTML5 introduces a number of APIs (Application Programming Interfaces) that help in creating Web applications. These can be used together with the new elements introduced for applications.

API name Description Support
Media elements An API for playing of video and audio which can be used with the new <video> and <audio> elements. Opera provides support with the following exceptions:
  • buffered, seekable and played IDL attributes always return empty TimeRanges objects.
  • playbackRate and defaultPlaybackRate do not affect playback speed or direction.
 Partial
Application cache An API that enables offline Web applications. Yes
Custom scheme and content handlers An API that allows a Web application to register itself for certain protocols or media types. No
Editing This API works in combination with a new global contenteditable attribute.
  • The "opera-defaultBlock" vendor-specific extension for document.execCommand controls which element should be used as the default element for paragraphs. Supported values are "div" and "p".
 Yes
Drag and drop This API works in combination with a draggable attribute. No
History An API that exposes the history and allows pages to add to it to prevent breaking the back button. Yes

Extensions to HTMLDocument

HTML5 has extended the HTMLDocument interface from DOM Level 2 HTML in a number of ways. The interface is now implemented on all objects implementing the Document interface so it stays meaningful in a compound document context. It also has several noteworthy new members.

Extension name Description Support
getElementsByClassName() This is used to select elements by their class name.
The way this method is defined will allow it to work for any
content with class attributes and a Document
object such as SVG and MathML. 		Yes
innerHTML This is used as an easy way to parse and serialize
an HTML or XML document. This attribute was
previously only available on HTMLElement
in Web browsers and not part of any standard.
Note: Opera does not support innerHTML on XML documents. 		Yes
activeElement This determines which element in the document is currently
focused and must return it. 		Yes
hasFocus This determines whether the document has focus respectively.
It returns true if the document has focus; otherwise, it returns false. 		Yes
getSelection() This returns an object that represents the current selection(s). Yes

Extensions to HTMLElement

The HTMLElement interface has also gained several extensions in HTML5.

Extension name Description Support
getElementsByClassName() This is a scoped version of the one found on HTMLDocument. Yes
innerHTML This is used as an easy way to parse and serialize
a HTML or XML document. Note: Opera does not support innerHTML
on XML documents. 		Yes
dataset The dataset attribute provides convenient accessors for all the data-* attributes on an element. Yes
classList This is a convenient accessor for className. The object it
returns exposes the methods has(), add(),
remove(), and toggle() for manipulating the
element's classes. Note: Opera does support className. 		Yes
relList The <a>, <area> and <link>
elements have a similar attribute called relList that provides
the same functionality (as shown above in classList)
for the rel attribute. 		No

Documentation

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