Website Quality Alert
Incorrect content language code
The code of the content language defined for the web page is not amongst the list of preferred codes.
We applying heuristics of common misspellings and a list of common non-standard names to determine the content language, but strictly speaking, the content language is undefined in these cases.
The list of known language codes includes the ISO 639-1 and ISO 639-2 codes, where the two letter code must be used if available. The Internet Assigned Numbers Authority (IANA) provides the official language subtag registry.
According to the W3C Internationalization Best Practices, language information is useful for things such as authoring tools, translation tools, accessibility, font selection, page rendering, search, and scripting. In practice, we see that localized search engines (such as google.it) make use of language information, so that missing or incorrect information may have a negative impact of search engine ranking. It is also likely to affect site visitors who use screen readers or spell checkers, in case an input from the user is expected.
Always specify the content language with the preferred language code, if possible using the ISO 639 codes.