What standard says <http://news.ycombinator.com/>? The appendix of http://www.ietf.org/rfc/rfc1738.txt says <URL:http://news.ycombinator.com/>.
"The characters '<' and '>' are unsafe because they are used as the delimiters around URLs in free text".
The RFC itself uses "<URL:...>" because it already uses "<...>" for BNF non-terminals, which are much more common than URLs in the RFC.
Enjoy your undeserved upvote :)