Wikimedia Bugzilla is closed!

Currently there are some differences between the normalizations in Title.js and Title.php:

* Invalid characters:
   Title.js replaces [, ], and other invalid characters with _.
* Unicode control characters:
   Title.php removes some control characters, while Title.js leaves them in or
   replaces them with _.
* Whitespace normalization:
   Title.php normalizes a huge variety of whitespace (notably NBSP), while
   Title.js only treats _ the same as a blank.
* HTML entities:
   Title.php replaces HTML entities with the corresponding character.
* URL encoding:
   At some point %-encoded characters are resolved in PHP, at least they are
   possible in wikilinks.

mediawiki.Title.js should aim for consistency with the PHP version.