Comment Re:Why? (Score 1) 162
No. Dotted-decimal notation is the only acceptable way to represent an IPv4 address in a URI according to RFC 3986. That RFC even specifically mentions that many implementations that process URIs make use of platform-dependent system routines, such as gethostbyname() and inet_aton(), to translate the string literal to an actual IP address and that may allow ways around filtering software.
If it is explicitly against the RFC then browsers shouldn't allow it.
http://tools.ietf.org/html/rfc3986#page-20
http://tools.ietf.org/html/rfc3986#section-7.4