HTML 5.2

New features

• The dialog element.

• Integration with the JavaScript module system of [ECMA-262].

• Referrer policy [REFERRERPOLICY].

• Update ARIA reference to [wai-aria-1.1], which introduces new features to improve accessibility.

• The nonce attribute for link as used in Content Security Policy [CSP3].

• The allowpaymentrequest attribute of iframe, for integration with the Payment Request API [PAYMENT-REQUEST].

• The allow-presentation value for the sandbox attribute of iframe, for integration with the Presentation API [PRESENTATION-API].

• The canonical value for the rel attribute of links.

• The noreferrer link type value for [SECURE-CONTEXTS].

• The apple-touch-icon value for the rel attribute to allow the use of the size attribute in the link element.

• The registerContentHandler(), isContentHandlerRegistered() and isProtocolHandlerRegistered() methods.

• The innerText IDL attribute for HTMLElement.

• Define the about:html-kind URL for MP4 media track integration.

• Integrate the Should element be blocked a priori by Content Security Policy? of [CSP3]

Features removed

• The keygen, menu and menuitem elements.

• The inputmode attribute for textual input elements, and the dropzone attributes.

• The showModalDialog method.

• The Plugin API has been marked as obsolete.

Fixing bugs and matching reality better

• Stop media resource requests from non-network sources delaying the load event.

• Remove arbitrary upper limits on refresh rates.

• Coordinates for ismap no longer include the image’s border in calculation.

• Update accesskey definition to require a single printable character.

• Fix the activation algorithm for summary to match reality.

• Fix the algorithm to determine row and column headers for table.

• Update the rendering of summary

• Reflecting a broken URL returns the unparsed value

• currentScript may return SVGScriptElement.

• Resetting a textarea resets its dirty value flag.

• document.open() and document.close() check for XML document.

• HashChangeEvent URLs are USVString instead of DOMString.

• Selection members' types are nullable.

• data: URLs are treated as a separate origin.

• Sadly, elements that are only focusable because they have a tabindex attribute generally will not fire a click event when activated with a non-pointer device.

• Navigation for sandboxed contexts

• Updated allowable role values in line with [html-aria]

The following constructions are now valid HTML:

style within the body.

Multiple main elements in the DOM, so long as only one is visible to the user.

The presentation for the img element.

div as a child of a dl element.

dfn as a descendent of an li element that contains a definition of the term defined.

Headings within legend in a fieldset.

Empty option element as a child of datalist.

Comments containing two consecutive hyphens, or ending with a hyphen, in the HTML syntax.

Remove restrictions on BiDi algorithm section

The following constructions are no longer valid HTML:

role values for a caption element.

Inline blocks, inline tables, or floated and positioned block-level elements as children of a p element.

Content with the HTML4 or XHTML1 strict doctype.

New concepts

• Added serialized state and creator context security.

• Added an algorithm to determine whether content is allowed to use certain powerful, hence potentially risky, features.

• Added the WindowOrWorkerGlobalScope mixin as a convenience.

Editorial clarifications

• Browsers should represent punycode addresses as natural unicode text for the email input type.

• Clarify the concept of last frame time for the seekable IDL attribute

• Browsers that use the the suggestions source element to filter suggestions should implement substring matching on the label attribute.

• Users should be able to interact with area elements whether or not they use a pointing device.