[CSS Level 4 pseudo-class] :user-error

[kevinSuttle]

https://www.w3.org/TR/2013/WD-selectors4-20130502/#user-pseudos

[cvrebert]

https://drafts.csswg.org/selectors/#user-pseudos

[kevinSuttle]

w3c/csswg-drafts#579

[chharvey]

:user-error was renamed to :user-invalid.

Also, this issue should be covered by #1058 , no?

[Schweinepriester]

Available via MDN: https://caniuse.com/mdn-css_selectors_user-invalid

[GPHemsley]

https://developer.mozilla.org/en-US/docs/Web/CSS/:user-invalid

(via mdn/browser-compat-data#2829, mdn/browser-compat-data#7431)