<q> is a valid wikitext tag, which surrounds its contents with quotes. However, it is not localized: It always displays the English-style quotes.
Something like the following should be added into the global stylesheet:
:lang(en) q { quotes: "“" "”" "‘" "’"; } :lang(ru) q { quotes: "«" "»" "„" "“"; } :lang(cs) q { quotes: "„" "“" "," "‘"; } ...
Requested at cswiktionary:WS:PLT.