HTML Living Standard Web Standard

The HTML Living Standard describes the behavior of HTML elements and attributes. It is continuously maintained and supersedes HTML4, XHTML1, and all previous HTML specifications, and is sometimes referred to as HTML5.

• HTML Living Standard

Rules

• Body element is hidden
• ARIA role conflict
• Null alt role conflict
• bdo must have a dir attribute
• label elements may not contain multiple form controls
• for must refer to a non-hidden form control
• section must not appear inside address
• nav must not appear inside address
• article must not appear inside address
• aside must not appear inside address
• footer must not appear inside header element
• footer must not appear inside footer element
• footer must not appear inside address element
• h1 must not appear inside address
• h2 must not appear inside address
• h3 must not appear inside address
• h4 must not appear inside address
• h5 must not appear inside address
• h6 must not appear inside address
• header must not appear inside footer
• header must not appear inside address
• header must not appear inside header
• table must not appear inside caption
• summary is obsolete
• a cannot have clickable ancestor a
• details cannot have clickable ancestor a
• embed cannot have clickable ancestor a
• iframe cannot have clickable ancestor a
• label cannot have clickable ancestor a
• a cannot have clickable ancestor button
• details cannot have clickable ancestor button
• embed cannot have clickable ancestor button
• iframe cannot have clickable ancestor button
• label cannot have clickable ancestor button
• button cannot have clickable ancestor a
• textarea cannot have clickable ancestor a
• select cannot have clickable ancestor a
• input cannot have clickable ancestor a
• button cannot have clickable ancestor button
• textarea cannot have clickable ancestor button
• select cannot have clickable ancestor button
• input cannot have clickable ancestor button
• button inside label with for must have an id matching for
• textarea inside label with for must have an id matching for
• select inside label with for must have an id matching for
• input inside label with for must have an id matching for
• video with controls must not appear as a descendant of a
• audio with controls must not appear as a descendant of a
• video with controls must not appear as a descendant of button
• audio with controls must not appear as a descendant of button
• menu with type=toolbar must not appear inside a
• menu with type=toolbar must not appear inside button
• img with usemap must not appear inside a
• img with usemap must not appear inside button
• object with usemap must not appear inside a
• object with usemap must not appear inside button
• area must be inside a map element
• img with ismap must be inside an a element with an href
• list attribute must refer to a datalist element
• input type=button must not have empty value attribute
• label attribute must not be empty
• default attribute can only appear on one track inside audio or video
• id on a map element must be identical to the name attribute
• Multiple selected options only allowed when select has multiple attribute
• select with required must contain an option element
• First option in a required select dropdown must have an empty value or empty text content
• language=JavaScript can only be used with type='text/javascript'
• script cannot have attribute charset unless src is specified
• script cannot have attribute defer unless src is specified
• script cannot have attribute async unless src or type=module is specified
• progress must not appear inside another progress element
• Progress value must not be greater than max
• Progress value must not be greater than 1.0
• meter must not appear inside another meter element
• min must not be greater than value
• value must be greater than or equal to 0 if min not specified
• value must not be greater than max
• value must be less than or equal to 1 if max not specified
• min must not be greater than max
• max must be greater than or equal to 0 if min not specified
• min must be less than or equal to 1 if max not specified
• min must not be greater than low
• low must be greater than or equal to 0 if min not specified
• min must not be greater than high
• high must be greater than or equal to 0 if min not specified
• low must not be greater than high
• high must not be greater than max
• high must be less than or equal to 1 if max not specified
• low must not be greater than max
• low must be less than or equal to 1 if max not specified
• min must not be greater than optimum
• optimum must be greater than or equal to 0 if min not specified
• optimum must not be greater than max
• optimum must be less than or equal to 1 if max not specified
• acronym is obsolete
• applet is obsolete
• center is obsolete
• font is obsolete
• big is obsolete
• strike is obsolete
• tt is obsolete
• basefont is obsolete
• dir is obsolete
• frameset is obsolete
• noframes is obsolete
• coords on a is obsolete
• shape on a is obsolete
• urn on a is obsolete
• charset on a is obsolete
• methods on a is obsolete
• target on link is obsolete
• urn on link is obsolete
• charset on link is obsolete
• methods on link is obsolete
• nohref on area is obsolete
• name on embed is obsolete
• profile on head is obsolete
• version on html is obsolete
• name on img is obsolete
• usemap on input is obsolete
• type on the li element is obsolete
• type on the ul element is obsolete
• scheme on meta is obsolete
• meta http-equiv=content-language is obsolete
• archive on object is obsolete
• classid on object is obsolete
• code on object is obsolete
• codebase on object is obsolete
• codetype on object is obsolete
• declare on object is obsolete
• standby on object is obsolete
• name on option is obsolete
• type on param is obsolete
• valuetype on param is obsolete
• language on script is obsolete
• scope on td is obsolete
• abbr on td is obsolete
• axis on td is obsolete
• axis on th is obsolete
• align on caption is obsolete
• align on iframe is obsolete
• align on img is obsolete
• align on input is obsolete
• align on object is obsolete
• align on embed is obsolete
• align on legend is obsolete
• align on table is obsolete
• align on hr is obsolete
• align on div is obsolete
• align on h1 is obsolete
• align on h2 is obsolete
• align on h3 is obsolete
• align on h4 is obsolete
• align on h5 is obsolete
• align on h6 is obsolete
• align on p is obsolete
• align on col is obsolete
• align on colgroup is obsolete
• align on tbody is obsolete
• align on td is obsolete
• align on tfoot is obsolete
• align on th is obsolete
• align on thead is obsolete
• align on tr is obsolete
• width on col is obsolete
• width on colgroup is obsolete
• width on hr is obsolete
• width on pre is obsolete
• width on table is obsolete
• width on td is obsolete
• width on th is obsolete
• char on col is obsolete
• char on colgroup is obsolete
• char on tbody is obsolete
• char on td is obsolete
• char on tfoot is obsolete
• char on th is obsolete
• char on thead is obsolete
• char on tr is obsolete
• charoff on col is obsolete
• charoff on colgroup is obsolete
• charoff on tbody is obsolete
• charoff on td is obsolete
• charoff on tfoot is obsolete
• charoff on th is obsolete
• charoff on thead is obsolete
• charoff on tr is obsolete
• valign on col is obsolete
• valign on colgroup is obsolete
• valign on tbody is obsolete
• valign on td is obsolete
• valign on tfoot is obsolete
• valign on th is obsolete
• valign on thead is obsolete
• valign on tr is obsolete
• alink on body is obsolete
• background on body is obsolete
• bgcolor on body is obsolete
• link on body is obsolete
• bottommargin on body is obsolete
• marginheight on the body element is obsolete
• leftmargin on body is obsolete
• rightmargin on body is obsolete
• topmargin on the body element is obsolete
• marginwidth on the body element is obsolete
• text on body is obsolete
• vlink on body is obsolete
• clear on br is obsolete
• hspace on embed is obsolete
• vspace on embed is obsolete
• noshade on the hr element is obsolete
• size on the hr element is obsolete
• color on the hr element is obsolete
• compact on the dl element is obsolete
• compact on the menu element is obsolete
• compact on the ol element is obsolete
• compact on the ul element is obsolete
• allowtransparency on iframe is obsolete
• frameborder on iframe is obsolete
• marginheight on iframe is obsolete
• marginwidth on iframe is obsolete
• scrolling on iframe is obsolete
• hspace on the img element is obsolete
• hspace on the object element is obsolete
• vspace on the img element is obsolete
• vspace on the object element is obsolete
• border on the img element is obsolete
• border on the object element is obsolete
• bgcolor on the table element is obsolete
• border on the table element is obsolete
• cellpadding on the table element is obsolete
• cellspacing on the table element is obsolete
• frame on the table element is obsolete
• rules on the table element is obsolete
• bgcolor on the td element is obsolete
• bgcolor on the th element is obsolete
• height on the td element is obsolete
• height on the th element is obsolete
• nowrap on the td element is obsolete
• nowrap on the th element is obsolete
• bgcolor on the tr element is obsolete
• xml:lang requires lang with same value to be present
• border on img element is obsolete
• language on the script element is obsolete
• name on the a element is obsolete
• video element has more than one default track
• audio element has more than one default track
• form cannot have ancestor form
• progress cannot have ancestor progress
• meter cannot have ancestor meter
• dfn cannot have ancestor dfn
• noscript cannot have ancestor noscript
• label cannot have ancestor label
• address cannot have ancestor address
• section cannot have ancestor address
• nav cannot have ancestor address
• article cannot have ancestor address
• header cannot have ancestor header
• header cannot have ancestor footer
• header cannot have ancestor address
• footer cannot have ancestor header
• footer cannot have ancestor footer
• header cannot have ancestor dt
• footer cannot have ancestor dt
• article cannot have ancestor dt
• nav cannot have ancestor dt
• section cannot have ancestor dt
• h1 cannot have ancestor dt
• h2 cannot have ancestor dt
• h3 cannot have ancestor dt
• h4 cannot have ancestor dt
• h5 cannot have ancestor dt
• h6 cannot have ancestor dt
• hgroup cannot have ancestor dt
• header cannot have ancestor th
• footer cannot have ancestor th
• article cannot have ancestor th
• nav cannot have ancestor th
• section cannot have ancestor th
• h1 cannot have ancestor th
• h2 cannot have ancestor th
• h3 cannot have ancestor th
• h4 cannot have ancestor th
• h5 cannot have ancestor th
• h6 cannot have ancestor th
• hgroup cannot have ancestor th
• footer cannot have ancestor address
• h1 cannot have ancestor address
• h2 cannot have ancestor address
• h3 cannot have ancestor address
• h4 cannot have ancestor address
• h5 cannot have ancestor address
• h6 cannot have ancestor address
• table cannot have ancestor caption
• a cannot have ancestor a
• a cannot have ancestor button
• button cannot have ancestor a
• button cannot have ancestor button
• details cannot have ancestor a
• details cannot have ancestor button
• dialog cannot have ancestor a
• dialog cannot have ancestor button
• embed cannot have ancestor a
• embed cannot have ancestor button
• iframe cannot have ancestor a
• iframe cannot have ancestor button
• label cannot have ancestor a
• label cannot have ancestor button
• select cannot have ancestor a
• select cannot have ancestor button
• textarea cannot have ancestor a
• textarea cannot have ancestor button
• main cannot have ancestor a
• main cannot have ancestor address
• main cannot have ancestor article
• main cannot have ancestor aside
• main cannot have ancestor audio
• main cannot have ancestor blockquote
• main cannot have ancestor canvas
• main cannot have ancestor caption
• main cannot have ancestor dd
• main cannot have ancestor del
• main cannot have ancestor details
• main cannot have ancestor dialog
• main cannot have ancestor dt
• main cannot have ancestor fieldset
• main cannot have ancestor figure
• main cannot have ancestor footer
• main cannot have ancestor header
• main cannot have ancestor ins
• main cannot have ancestor li
• main cannot have ancestor main
• main cannot have ancestor map
• main cannot have ancestor nav
• main cannot have ancestor noscript
• main cannot have ancestor object
• main cannot have ancestor section
• main cannot have ancestor slot
• main cannot have ancestor td
• main cannot have ancestor th
• main cannot have ancestor video
• a cannot have ancestor with role=button
• a cannot have ancestor with role=link
• button cannot have ancestor with role=button
• button cannot have ancestor with role=link
• details cannot have ancestor with role=button
• details cannot have ancestor with role=link
• dialog cannot have ancestor with role=button
• dialog cannot have ancestor with role=link
• embed cannot have ancestor with role=button
• embed cannot have ancestor with role=link
• iframe cannot have ancestor with role=button
• iframe cannot have ancestor with role=link
• label cannot have ancestor with role=button
• label cannot have ancestor with role=link
• select cannot have ancestor with role=button
• select cannot have ancestor with role=link
• textarea cannot have ancestor with role=button
• textarea cannot have ancestor with role=link
• Element with tabindex cannot have ancestor with role=button
• Element with tabindex cannot have ancestor with role=link
• audio with controls cannot have ancestor with role=button
• audio with controls cannot have ancestor with role=link
• img with usemap cannot have ancestor with role=button
• img with usemap cannot have ancestor with role=link
• input cannot have ancestor with role=button
• input cannot have ancestor with role=link
• menu with toolbar cannot have ancestor with role=button
• menu with toolbar cannot have ancestor with role=link
• object with usemap cannot have ancestor with role=button
• object with usemap cannot have ancestor with role=link
• video with controls cannot have ancestor with role=button
• video with controls cannot have ancestor with role=link
• role=button cannot have ancestor with role=button
• role=button cannot have ancestor with role=link
• role=checkbox cannot have ancestor with role=button
• role=checkbox cannot have ancestor with role=link
• role=combobox cannot have ancestor with role=button
• role=combobox cannot have ancestor with role=link
• role=grid cannot have ancestor with role=button
• role=grid cannot have ancestor with role=link
• role=gridcell cannot have ancestor with role=button
• role=gridcell cannot have ancestor with role=link
• role=listbox cannot have ancestor with role=button
• role=listbox cannot have ancestor with role=link
• role=menu cannot have ancestor with role=button
• role=menu cannot have ancestor with role=link
• role=menubar cannot have ancestor with role=button
• role=menubar cannot have ancestor with role=link
• role=menuitem cannot have ancestor with role=button
• role=menuitem cannot have ancestor with role=link
• role=menuitemcheckbox cannot have ancestor with role=button
• role=menuitemcheckbox cannot have ancestor with role=link
• role=menuitemradio cannot have ancestor with role=button
• role=menuitemradio cannot have ancestor with role=link
• role=option cannot have ancestor with role=button
• role=option cannot have ancestor with role=link
• role=radio cannot have ancestor with role=button
• role=radio cannot have ancestor with role=link
• role=scrollbar cannot have ancestor with role=button
• role=scrollbar cannot have ancestor with role=link
• role=searchbox cannot have ancestor with role=button
• role=searchbox cannot have ancestor with role=link
• role=slider cannot have ancestor with role=button
• role=slider cannot have ancestor with role=link
• role=spinbutton cannot have ancestor with role=button
• role=spinbutton cannot have ancestor with role=link
• role=switch cannot have ancestor with role=button
• role=switch cannot have ancestor with role=link
• role=tab cannot have ancestor with role=button
• role=tab cannot have ancestor with role=link
• role=textbox cannot have ancestor with role=button
• role=textbox cannot have ancestor with role=link
• role=treeitem cannot have ancestor with role=button
• role=treeitem cannot have ancestor with role=link
• Element link not allowed in body
• div with parent dl has invalid role
• li with ancestor role=menu or menubar has invalid role
• li with ancestor role=tablist must have role=tab
• role=caption must have parent with role=figure or grid or table or treegrid
• role=cell must have parent with role=row
• role=option must have parent with role=listbox
• role=menuitem must have parent with role=menu or menubar
• role=menuitemcheckbox must have parent with role=menu or menubar
• role=menuitemradio must have parent with role=menu or menubar or group
• role=tab must have parent with role=tablist
• role=treeitem must have parent with role=tree or group
• role=listitem must have parent with role=list
• role=gridcell must have parent with role=row
• role=columnheader must have parent with role=row
• role=rowheader must have parent with role=row
• role=row must have parent with role=grid or rowgroup or treegrid or table
• role=rowgroup must have parent with role=grid or treegrid or table
• role=feed must contain role=article
• role=grid must contain role=row or rowgroup
• role=list must contain role=listitem
• role=listbox must contain role=option
• role=menu must contain role=menuitem or menuitemcheckbox or menuitemradio
• role=menubar must contain role=menuitem or menuitemcheckbox or menuitemradio
• role=radiogroup must contain role=radio
• role=row must contain role=cell or columnheader or gridcell or rowheader
• role=rowgroup must contain role=row
• role=table must contain role=row or rowgroup
• role=tablist must contain role=tab
• role=tree must contain role=treeitem
• role=treegrid must contain role=row or rowgroup
• title must not be empty
• option element must not be empty
• usemap refers to non-existent map
• Duplicate dt terms in dl
• Autonomous custom elements must not use is
• form attribute must refer to form element
• Only utf-8 is allowed for form accept-charset
• list attribute must refer to datalist element
• Only utf-8 is allowed for meta charset
• Only utf-8 is allowed for script charset
• select must not use autocomplete=webauthn
• Only text/css is allowed for style type
• type is redundant on style
• Use figcaption instead of table caption
• link scope can only be used with rel=serviceworker
• link updateviacache can only be used with rel=serviceworker
• link workertype can only be used with rel=serviceworker
• blocking can only be used with modulepreload, preload or stylesheet
• link color can only be used with rel=mask-icon
• link disabled can only be used with rel=stylesheet
• link fetchpriority can only be used with external resource types
• link must have href or imagesrcset
• link with imagesizes must have imagesrcset
• link with imagesizes must have as=image
• link with imagesrcset must have as=image
• link with imagesizes must have rel=preload
• link with imagesrcset must have rel=preload
• link sizes can only be used with rel=icon, rel=apple-touch-icon or rel=apple-touch-icon-precomposed
• link as only allowed with rel=preload or rel=modulepreload
• Alternate stylesheets must have a title
• link integrity can only be used with rel=stylesheet, rel=preload or rel=modulepreload
• script fetchpriority should only be used with src
• script with integrity attribute must have src
• script with redundant type attribute
• script must not have async
• script must not have blocking
• script must not have defer
• script must not have fetchpriority
• script must not have integrity
• script with type=module must not have blocking
• script with type=module must not have fetchpriority
• script with type=module must not have integrity
• script with type=module must not have defer
• script with type=module must not have nomodule
• script with type=importmap must not have async
• script with type=importmap must not have blocking
• script with type=importmap must not have crossorigin
• script with type=importmap must not have defer
• script with type=importmap must not have fetchpriority
• script with type=importmap must not have integrity
• script with type=importmap must not have nomodule
• script with type=importmap must not have referrerpolicy
• script with type=importmap must not have src
• script with type=speculationrules must not have async
• script with type=speculationrules must not have blocking
• script with type=speculationrules must not have crossorigin
• script with type=speculationrules must not have defer
• script with type=speculationrules must not have fetchpriority
• script with type=speculationrules must not have integrity
• script with type=speculationrules must not have nomodule
• script with type=speculationrules must not have referrerpolicy
• script with type=speculationrules must not have src
• script with a data type must not have async
• script with a data type must not have blocking
• script with a data type must not have crossorigin
• script with a data type must not have defer
• script with a data type must not have fetchpriority
• script with a data type must not have integrity
• script with a data type must not have nomodule
• script with a data type must not have referrerpolicy
• script with a data type must not have src
• meta with media attribute must have name=theme-color
• Avoid meta viewports that prevent zooming
• Multiple meta elements with name=description
• Section lacks heading
• Article lacks heading
• Multiple meta charset elements
• Multiple meta elements with charset and content-type
• Multiple meta elements with http-equiv=content-type
• Page has multiple h1 elements
• Page has multiple main elements
• Multiple elements with role=main
• xml:lang without matching lang
• blink is obsolete
• keygen is obsolete
• marquee is obsolete
• menuitem is obsolete
• nobr is obsolete
• param is obsolete
• contextmenu is obsolete
• datafld is obsolete
• dataformatas is obsolete
• datasrc is obsolete
• datapagesize on table is obsolete
• longdesc on img is obsolete
• type attribute on menu is obsolete
• for attribute on script is obsolete
• event attribute on script element is obsolete
• itemid can only be used on elements with itemscope and itemtype
• itemref can only be used on elements with itemscope
• itemtype can only be used on elements with itemscope
• img with alt='' must not have role
• Page has multiple autofocus elements
• typemustmatch can only be used when data and type are specified
• base must appear before link and script
• bdo must not use dir=auto
• headingoffset must be between 0 and 8
• No lang on html element
• img must have an alt attribute
• Broken aria-activedescendant ID reference
• Broken commandfor ID reference
• Unsupported SVG version
• aria-hidden not allowed on base
• aria-hidden not allowed on col
• aria-hidden not allowed on colgroup
• aria-hidden not allowed on head
• aria-hidden not allowed on html
• aria-hidden not allowed on input with type=hidden
• aria-hidden not allowed on link
• aria-hidden not allowed on map
• aria-hidden not allowed on meta
• aria-hidden not allowed on noscript
• aria-hidden not allowed on param
• aria-hidden not allowed on script
• aria-hidden not allowed on slot
• aria-hidden not allowed on source
• aria-hidden not allowed on style
• aria-hidden not allowed on template
• aria-hidden not allowed on title
• aria-hidden not allowed on track
• aria-hidden not allowed on elements with hidden=until-found
• aria- attributes are not allowed on input elements with type=hidden
• role=article unnecessary for article
• role=complementary unnecessary for aside
• role=document unnecessary for body
• role=button unnecessary for button
• role=listbox unnecessary for datalist
• role=definition unnecessary for dd
• role=group unnecessary for details
• role=term unnecessary for dfn
• role=dialog unnecessary for dialog
• role=term unnecessary for dt
• role=group unnecessary for fieldset
• role=figure unnecessary for figure
• role=contentinfo unnecessary for footer
• role=form unnecessary for form
• role=heading unnecessary for h1
• role=heading unnecessary for h2
• role=heading unnecessary for h3
• role=heading unnecessary for h4
• role=heading unnecessary for h5
• role=heading unnecessary for h6
• role=banner unnecessary for header
• role=separator unnecessary for hr
• role=listitem unnecessary for li
• role=link unnecessary for link
• role=main unnecessary for main
• role=math unnecessary for math
• role=navigation unnecessary for nav
• role=list unnecessary for ol
• role=option unnecessary for option
• role=status unnecessary for output
• role=progressbar unnecessary for progress
• role=region unnecessary for section
• role=listbox unnecessary for select
• role=combobox unnecessary for select
• role=deletion unnecessary for s
• role=button unnecessary for summary
• role=table unnecessary for table
• role=rowgroup unnecessary for tbody
• role=textbox unnecessary for textarea
• role=rowgroup unnecessary for tfoot
• role=rowgroup unnecessary for thead
• role=cell unnecessary for td
• role=row unnecessary for tr
• role=list unnecessary for ul
• role=columnheader unnecessary for th
• select only allows combobox menu and combobox roles
• meter does not need a role
• optgroup does not need a role
• role=button unnecessary for input type=button
• role=checkbox unnecessary for input type=checkbox
• role=button unnecessary for input type=image
• role=spinbutton unnecessary for input type=number
• role=radio unnecessary for input type=radio
• role=slider unnecessary for input type=range
• role=button unnecessary for input type=reset
• role=button unnecessary for input type=submit
• role=button unnecessary for button type=menu
• role=toolbar unnecessary for menu type=toolbar
• role=textbox unnecessary for input type=email and no list attribute
• role=textbox unnecessary for input type=tel and no list attribute
• role=textbox unnecessary for input type=text and no list attribute
• role=searchbox unnecessary for input type=search and no list attribute
• role=textbox unnecessary for input type=url and no list attribute
• role=combobox unnecessary for input type=email and a list attribute
• role=combobox unnecessary for input type=tel and a list attribute
• role=combobox unnecessary for input type=text and a list attribute
• role=combobox unnecessary for input type=search and a list attribute
• role=combobox unnecessary for input type=url and a list attribute
• aria-haspopup should not be used on input type=email with a list attribute
• aria-haspopup should not be used on input type=tel with a list attribute
• aria-haspopup should not be used on input type=text with a list attribute
• aria-haspopup should not be used on input type=search with a list attribute
• aria-haspopup should not be used on input type=url with a list attribute
• role=listitem unnecessary for li inside ol or ul
• role=link unnecessary for a, area and link with href
• role=combobox unnecessary for select elements with size less than two
• role=listbox unnecessary for select with multiple or size greater than one
• Non-empty img alt used with role=none or role=presentation
• img with no alt cannot have a role
• img with no alt cannot have aria- attributes
• figure with a figcaption must not have a role
• role forbidden on td th and tr elements inside tables
• aria-colspan not needed with colspan
• aria-colspan must match colspan
• aria-disabled not needed with disabled
• aria-disabled=false cannot be used with disabled
• aria-hidden not needed with hidden
• aria-hidden=false cannot be used with hidden
• aria-readonly not needed with readonly
• aria-readonly=false cannot be used with readonly
• aria-required not needed with required
• aria-required=false cannot be used with required
• aria-rowspan not needed with rowspan
• aria-rowspan must match rowspan
• autocomplete only allowed with some input types
• list only allowed with some input types
• maxlength only allowed with some input types
• minlength only allowed with some input types
• pattern only allowed with some input types
• placeholder only allowed with some input types
• readonly only allowed with some input types
• required only allowed with some input types
• size only allowed with some input types
• aria-valuemax forbidden on progress with max attribute
• aria-valuemax redundant on progress
• aria-valuemax forbidden on meter with max attribute
• aria-valuemax redundant on meter
• aria-valuemin forbidden on meter with min attribute
• aria-valuemin redundant on meter
• aria-valuemax forbidden on input with max attribute
• aria-valuemax redundant on input
• aria-valuemin forbidden on input with min attribute
• aria-valuemin redundant on input
• aria-disabled=true should not be used on links
• aria-checked must not be used on input with type=radio or type=checkbox
• aria-multiselectable should not be used on select
• aria-selected should not be used on option
• aria-placeholder must not be used with placeholder
• aria-readonly=true must not be used with contenteditable
• ARIA label used on role that prohibits naming
• ARIA global property used on prohibited role
• directory role is deprecated
• aria-dropeffect and aria-grabbed are deprecated
• aria-disabled is deprecated on non-interactive roles
• aria-errormessage is deprecated on non-interactive roles
• aria-haspopup is deprecated on non-interactive roles
• aria-invalid is deprecated on non-interactive roles
• aria-pressed required on checkbox with role=button
• label must not have ARIA attributes or role
• summary must not have role
• aria-expanded not allowed with command
• aria-expanded not allowed with popovertarget
• Active role=tab without role=tabpanel
• Focusable role=separator must have aria-valuenow
• ARIA error
• Missing ARIA attribute
• HTML parsing error
• HTML Validation Error
• HTML validation warning
• HTML info message
• Unrecoverable parsing error
• Invalid language attribute
• ARIA role is invalid
• Invalid aria-controls value
• Autocomplete value is invalid
• Element caption not allowed here
• Element dd requires dl parent
• Element dt requires dl parent
• Element li requires ol or ul parent
• Element option requires select or optgroup parent
• Element summary requires details` parent
• img in noscript before body
• body seen when body already open
• Unknown value for rel