Disallow unknown pseudo-element selectors.
a::before {}
/** ↑
* This pseudo-element selector */
This rule considers pseudo-element selectors defined in the CSS Specifications, up to and including Editor's Drafts, to be known.
This rule ignores vendor-prefixed pseudo-element selectors.
The following patterns are considered violations:
a::pseudo {}
a::PSEUDO {}
a::element {}
The following patterns are not considered violations:
a:before {}
a::before {}
::selection {}
input::-moz-placeholder {}
Given:
["/^my-/", "pseudo-element"]
The following patterns are not considered violations:
a::pseudo-element {}
a::my-pseudo {}
a::my-other-pseudo {}