http is deprecated.

The folks at no-http.org would like to see the ubiquitous 'http:' removed from the beginning of all our URLs. So instead of linking to "http://example.com/" in your pages, you would link to just "//example.com/".

This is actually quite legal. RFC 1808 specifies that URLs beginning with '//' should just inherit the scheme of the base URL.

The argument for doing things this way is appealing to paranoid future-obsessed weirdos (like me). While HTTP is currently the most common way to deliver HTML, it could conceivably change in the future. Using scheme inheritance for links will prevent you from having to change them if or when things move away from HTTP. http is deprecate. long live http.

the above info. is an extract of the info posted on WebStandards, a community striving for standard based approach to the web, than the present browser based approach to the web.

URLs worth looking at;
WebStandards
A List Apart
World Web Consortium