The list of supported HTML and SVG elements is growing quite large, and it's very easy to miss a typo.

This rule checks each type selector to make sure that it is a known HTML or SVG element.

Noncompliant Code Example

blabla { /* Noncompliant: 'blabla' is not a known HTML or SVG element */
  color: red;
}

Compliant Solution

span {
  color: red;
}

List of Known HTML Elements

Extracted from the HTML Living Standard.

`a`	`abbr`	`address`
`area`	`article`	`aside`
`audio`	`b`	`base`
`bdi`	`bdo`	`blockquote`
`body`	`br`	`button`
`canvas`	`caption`	`cite`
`code`	`col`	`colgroup`
`data`	`datalist`	`dd`
`del`	`details`	`dfn`
`dialog`	`div`	`dl`
`dt`	`em`	`embed`
`fieldset`	`figcaption`	`figure`
`footer`	`form`	`h1`
`h2`	`h3`	`h4`
`h5`	`h6`	`head`
`header`	`hgroup`	`hr`
`html`	`i`	`iframe`
`img`	`input`	`ins`
`kbd`	`label`	`legend`
`li`	`link`	`main`
`map`	`mark`	`maxlength`
`menu`	`menuitem`	`meta`
`meter`	`minlength`	`nav`
`noscript`	`object`	`ol`
`optgroup`	`option`	`output`
`p`	`param`	`picture`
`pre`	`progress`	`q`
`rp`	`rt`	`ruby`
`s`	`samp`	`script`
`section`	`select`	`slot`
`small`	`source`	`span`
`strong`	`style`	`sub`
`summary`	`sup`	`table`
`tbody`	`td`	`template`
`textarea`	`tfoot`	`th`
`thead`	`time`	`title`
`tr`	`track`	`u`
`ul`	`var`	`video`
`wbr`

List of Known SVG Elements

Extracted from the W3C SVG Specifications.

`a`	`altGlyph`	`altGlyphDef`
`altGlyphItem`	`animate`	`animateColor`
`animateMotion`	`animateTransform`	`circle`
`clipPath`	`color-profile`	`cursor`
`defs`	`desc`	`ellipse`
`feBlend`	`feColorMatrix`	`feComponentTransfer`
`feComposite`	`feConvolveMatrix`	`feDiffuseLighting`
`feDisplacementMap`	`feDistantLight`	`feFlood`
`feFuncA`	`feFuncB`	`feFuncG`
`feFuncR`	`feGaussianBlur`	`feImage`
`feMerge`	`feMergeNode`	`feMorphology`
`feOffset`	`fePointLight`	`feSpecularLighting`
`feSpotLight`	`feTile`	`feTurbulence`
`filter`	`font`	`font-face`
`font-face-format`	`font-face-name`	`font-face-src`
`font-face-uri`	`foreignObject`	`g`
`glyph`	`glyphRef`	`hkern`
`image`	`line`	`linearGradient`
`marker`	`mask`	`metadata`
`missing-glyph`	`mpath`	`path`
`pattern`	`polygon`	`polyline`
`radialGradient`	`rect`	`script`
`set`	`stop`	`style`
`svg`	`switch`	`symbol`
`text`	`textPath`	`title`
`tref`	`tspan`	`use`
`view`	`vkern`

Exceptions

Type selectors starting with md- are considered as AngularJS Materials type selectors and do not raise any issue.
Custom type selectors can also be excluded through the Exclusions parameter.

stylelint Related Rules

selector-type-no-unknown