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 message
secondary option can accept the arguments of this rule.
The following patterns are considered problems:
a::pseudo {}
a::PSEUDO {}
a::element {}
The following patterns are not considered problems:
a:before {}
a::before {}
::selection {}
input::-moz-placeholder {}
Given:
["/^--my-/", "--pseudo-element"]
The following patterns are not considered problems:
a::--my-pseudo {}
a::--my-other-pseudo {}
a::--pseudo-element {}