Valid domain name registration for Unicode characters


I'm trying to figure out what is valid for domain name registration, apparently some Unicode characters are translated weirdly while others do not at all.

This address:

Translates to:


should translate to:


but for some reason the browser prevents it.

How is the format for these domains determined, and what is or isn't blocked by the browser? is a valid URL, while http://www.gοο is not. Yet Chrome only replaces the Unicode on the second URL.

It appears that you're trying to do an IDN homograph attack. The Wikipedia page nicely explains what Chrome is doing to stop you.