[css-variables] Example 5 might not represent best practices

(See Example 5)
https://www.w3.org/TR/css-variables-1/#defining-variables

A real-world example of custom property usage is easily separating out strings from where they’re used, to aid in maintenance of internationalization:

:root,
:root:lang(en) {--external-link: "external link";}
:root:lang(de) {--external-link: "externer Link";}

a[href^="http"]::after {content: " (" var(--external-link) ")"}

The variable declarations can even be kept in a separate file, to make maintaining the translations simpler.

This is perhaps questionable advice? On the one hand, if one has static strings in one's style sheet, using a variable and the :lang selector might be useful as a way of localizing the strings without repetition. On the other hand, there is some complexity to language matching here and it's probably not a best practice to have strings embedded in this way anyway. Our (I18N's) comment here might be "we wish you'd picked another example"

Start with Example 5 in the linked CSS Variables specification, especially the custom-property and :lang usage. Review the language-matching and internationalization concerns raised in the issue. Done means the example guidance has been resolved and the specification text reflects the agreed decision.