Each external or interwiki* link to a standard web site on a MediaWiki wiki has the scheme/protocol http: at the front of the href and link title. This is not necessary when the wiki is already at a http: URL.
Links like //www.example.com/ are perfectly valid and point to http://www.example.com/ in this context, just as a link to /wiki/Something is valid and unique on http://en.wikipedia.org/
If we remove the scheme from the emitted XHTML if identical to that of the site, ten bytes could be saved on each link. This would add up even if the site is gzipped; sadly, many - including Wikipedia's own front page; see bug 15944 - are not. On the current wikipedia.org it would save 1685 bytes, or 3%; if gzipped, it would save 59 bytes, or 0.4%. Still not bad for free!
It is not possible to specify a URL like [//example.com/ this] in the wikitext itself, either, but this is probably not a bad thing, as links should point to the same site when copied to another wiki.
- It will be possible to specify interwiki links without schemes once bug 18664 is fixed, and it might be necessary to modify the same code when fixing this one.
Version: unspecified
Severity: enhancement