This is a valid ipv4 address
The decoded URL for this submission is http://184.172.10.74/ — the server for Hacker News.Here's some other encodings you can use for the same address, they're all valid and recognised by most browsers and other software:http://3098282570/http://7393249866/http://0xb8.0xac.0x0a.0x4a/http://0270.0254.0012.0112/The source for this comment is an XSS filtering bypass tool by RSnake — http://ha.ckers.org/xsscalc.html