Website in Chinese 
Author: Stefan U.I built a website in Chinese for my translation service, URL: www.jiazhaofanyi.de. Because in Website X5 Evolution 12 Chinese is not included in the "languages of the website", I added a new language, named it "ZH - Chinese" and imported the content of the English version. Then I renamed some tags like "submit" or "reset" into Chinese "提交" and "重置", all the other tags were left in English because they don't appear on the website. Then I selected "ZH - Chinese" as "Language of the website". And as expected, "submit" and "reset" are displayed in Chinese on the website.
Unexpectedly however, the language attribute in the source code before the <head> is still lang="en-GB" instead of lang="zh-CN" or similar. I imagine that this situation is not very helpful in terms of SEO.
The website also includes a German version in a subdirectory but no entry page. The language attribute is lang="de-DE" as expected.
I would be glad if somebody could let me know how to solve this problem of the language attribute, may be by the example of another language added separately.
The language code is also entered with the variable lang_code in the speech center. You can customize it according to your needs.
JJ.
Author
Dear JJ. JUAG, thank you very much for your answer. I didn't know that I have to change this item in the Language Content Management window when adding a language not included in the language list, firstly because I hadn't noticed it and didn't know it exists, and secondly because it is an item in the source text and is not displayed visibly on the website.
I would suggest that this problem is added in the Online Help an in the PDF handbook where appropriate.
Best regards
Stefan