Search engines like google and yahoo don’t index 4XX pages as they don’t perform. Due to this fact, they’ll overlook any canonical tags pointing to these pages and sometimes wind up indexing the wrong (non-canonical) version of the webpage. Canonical tags are usually not the only solution to declare a site’s https://bookmarkfly.com/story18835548/the-%D0%90%D0%B2%D1%82%D0%BE%D0%BC%D0%B0%D1%82%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B5-%D1%82%D0%B5%D0%B3%D0%B8-hreflang-%D0%B8-%D0%BA%D0%B0%D0%BD%D0%BE%D0%BD%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B5-%D1%82%D0%B5%D0%B3%D0%B8-seo-diaries