Google this morning has sent out a brand new Google Search Console (formerly Webmaster Tools) notification to those who have implemented their hreflang incorrectly.
The subject of these notifications read "Incorrect Hreflang Implementation on xxx"
The body text reads:
Google had detected that some pages on your site have implemented the rel-alternate-hreflang tag incorrectly. In particular, there seems to be a problem with incorrrect language and region codes, or incorrect bi-directional linking (if page A links with hreflang to page B, there must be a link back from B to A as well). Google uses the hreflang attributes to serve the correct language or regional URL to the right users in search results.Until you correct the errors on the hreflang links, your website will not benefit from additional language or region targeting,
Gary Illyes told us on Twitter that are brand new messages and that it is about 15% of what they sent out for mobile usability issues. The mobile usability notifications via Google Search Console seemed to go to almost all webmasters, so 15% of that isn't a small number.
Dan Sharpe posted a screen shot of his error on Twitter:
A Google Webmaster Help thread has one user saying the notification is invalid as his implementation is correct. This webmaster said it was a false positive adding "It seems that the UNI code declared on the site is correct ( https://en.wikipedia.org/wiki/Friulian_language ) but it is only in ISO 639-2 and ISO 639-3. I've seen that google supports only ISO 639-1." And @mpezet also got one asking if this is now a bigger issue for SEO?
Joost de Valk from Yoast said he also just got a bunch, and shared a screen shot:
Forum discussion at Google Webmaster Help & Twitter.
