DNS doesn't accept single character domain
With several new TLDs it is possible to use a single character Domain. Even with some of the old well-known domains including .de in meanwhile it is possible to have a domain with only one character like "a.de". One of my customer owns such a domain with one of the new generic domains (in this case: .cymru). My solution was really simple: I changed the corresponding regex in /usr/local/ispconfig/interface/web/dns/form/dns_soa.tform.php and dns_slave.tform.php and then it worked.
Unfortunatelly it is not allowed to have a single character domain in all TLDs - so there are TLDs out there that still allow only two-character domains and even some that allow only three-character domains. So what is the right solution now? Including an intelligence that knows the minimal length for all TLDs? Or just my simple solution and allow one character in every case?