Language variants currently point to the same canonical URL. For example, on this page:
...there is a rel=”canonical” pointing to
This rel=”canonical” link asks search engines to index the Simplified Chinese page to represent the content on both pages, instead of separately indexing the Simplified Chinese and Traditional Chinese pages. Similar rel=”canonical” links are found on all zh-TW pages. Google is reporting that we see a similar problem on other Chinese (e.g. zh-SG) and Serbian content pages.
(this may be caused by the fix to bug 48402)
T53753: Links with language variants can't automatically jump to mobile sites
T71026: Canonical links may be in fallback encoding
T108443: Google doesn't honor canonical URLs of zh.wiki