non english (hebrew) chars in hostname

Question

Is it official? Where is it defined?

How can I transform between the english and non-english version, programmatically?

I see domains that google recognizes as hebrew, but the browser does not.

Examples:

http://www.xn----ogc3ffxd2br0d.com/ http://www.xn------wpehbcibg3bcah2ftaym6h.com/ http://www.xn----6hcesc7ap3c.ws/

Answer 1

http://en.wikipedia.org/wiki/Internationalized%5Fdomain%5Fname
http://en.wikipedia.org/wiki/Internationalized%5Fdomain%5Fname#ToASCII%5Fand%5FToUnicode

Answer 2

This is PUNYCODE with ACE prefix. The most popular library to handle this is

http://www.gnu.org/software/libidn/

Answer 3

Official, yes, it is IDN (Internationalized Domain Names) and it is defined (since 2003) in RFC 3490. (Although ".il" does not seem to allow them...)

There are several free software libraries to handle it:

• GNU libidn
• Verisign SDK
• JP NIC mDNkit/idnkit