Editing Help:User style (section)

=== Wikitext-controlled CSS ===
CSS can be controlled through JS by wikitext. For example, an HTML element "span" without content can, through its class and id, provide parameters for JS specifying CSS for any parts of the page. For example, if a page contains a "span" element with class FA and id ''lc'', [[MediaWiki:Monobook.js]] specifies the style and title of elements "li" of class interwiki-''lc'', thus controlling the style and title of the interlanguage link of language code ''lc'' in the margin, provided that the skin specifies this class interwiki-''lc'' (E.g., Cologne Blue specifies class='external' for each language, so it does not work for that skin.)