Our German customers frequently ask to start supporting the German “ß” character in Plesk. The character is also known as “sharp-s” or “Eszett”. So why don’t we just fix this problem?
Well, the answer is that the problem is not in Plesk and is not at the server-side at all. As you may know, international (in fact, national) characters were enabled in domain names with IDNA 2003 protocol, which introduced a procedure converting national names (German, Cyrillic, Chinese, etc) into something looking like xn--fa-hia.com. The idea was that national domain names would be equally converted into such an ASCII string on the client side (browser) and on the server side (DNS and Web servers), thus all existing Internet protocols would easily pass this converted ASCII string without any modification. Cool? Exactly! Except that original IDNA 2003 protocol didn’t support several characters properly and one of those was “ß”. It was interpreted as mere ‘ss’. So “faß.de” domain (for example) was processed as “fass.de”, ignoring the national character.