## Registering Internationalized Domain Names

An Internationalized Domain Name (IDN) is a standard for the domains that can contain characters other than the 36 basic ASCII ones permitted to date (a-z, 0-9, and -). This includes Latin letters with umlauts, accents and other diacritics, but it goes further than that and allows using completely different alphabets, such as the Greek and Cyrillic ones, as well as Chinese letters and characters.

Parallels Business Automation - Standard does not call for any specific configuration to start registering IDNs. A domain name entered as a Unicode string is converted into a permitted ASCII domain name.

A system called Internationalizing Domain Names in Applications (IDNA) was adopted as the chosen Internet standard for IDNs. The IDNA algorithm transforms domain names which include letters that are not available in ASCII into the format that can be handled by normal name servers. This transformation algorithm is based on the Punycode ASCII encoding of normalized (Nameprep) Unicode strings.

Note: The IDNA standard requires that the user who would like to view an IDN, has an IDN compatible application (browser, mail client, etc). The lists of such applications are available over the web.

Nameprep is the process of normalization, case-folding, etc. applied to a text before it is suitable to represent a domain name. Nameprep is defined in RFC 3491.

Punycode defined in RFC 3492 is the special encoding of Unicode strings into the limited character set supported by the DNS. The encoding is applied separately to each component of a domain name which is not represented solely within the ASCII character set, and a reserved prefix 'xn--' is added to the translated Punycode string.

Thus, an IDN always has two forms: one with special characters and the other in pure ASCII also called ACE (ASCII Compatible Encoding) or Punycode.

This ACE string is then entered into the DNS. The introduction of IDN means that in this case the entry in DNS is no longer identical with the domain name.

Not all the world's Top Level Domains (TLDs) are going to take on all these special letters and characters! Each registry responsible for a TLD is to decide for itself which subset to admit for the domains under it. In doing so, it strikes a balance between the limitations imposed by the standard and the particular needs of its local Internet Community. So please, keep this in mind when enabling INDs registration in Parallels Business Automation - Standard as system-wide option and then selecting TLDs per domain registration plug-ins.

Note: Some letters are not included in the IDNA Standard, such as the German '' (called 'scharfes s' or 'eszett'), which should be written as 'ss' instead. The eszett is a letter that is totally unique to the German alphabet. Unlike other letters, it has no upper case form, because it never occurs at the beginning of a word. The eszett is always normalized as 'ss' and thus, is typically shown as 'ss' in registered domain names. For example, wei.com will not be transformed to xn--wei-abc.com. Rather, it must be written as weiss.com and therefore is classified as a normal domain.

You can enable registering IDNs globally, as a system-wide setting, in Service Director - Domain Manager - Setup.

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