Pseudo element selectors should use two colons #523
Description
Currently, CSSLint doesn't warn if selectors for pseudo elements use the form :before or :after instead of ::before and ::after. The latter is the correct syntax as per the W3C specification (and has been since 2001).
The double-colon form is recognized by all modern browsers. The single-colon form is still widely used to accommodate IE8. IMO, at this point in time, CSSLint should emphasize the correct form over the backward compatible form.