Manual talk:$wgLegalTitleChars
This is a regex character class (i.e. a list of characters in a format suitable for a regular expression) that you want MediaWiki to allow in page titles despite being in the list of illegal characters.
Then why does the default value contain so many legal characters? Kevang 15:54, 20 February 2008 (UTC)
Apparently, $wgLegalTitleChars doesn't actually override the illegal chars. If a char is not present and accounted for in $wgLegalTitleChars, it's not permitted in a title. See lines 1265 and 1358-1361 in http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/Title.php?view=markup&pathrev=10960. Leaving this var blank would effectively cripple a site. Perhaps the description should be reworded to indicated that this var defines all legal title chars, but in no case overrides illegal chars? Brianko 22:19, 12 August 2010 (UTC)
[edit] Consequences of allowing < >
What would happen if these were added? --JimHu 18:51, 20 February 2008 (UTC)
[edit] Space character interfering with preg "x"-modifier
The space " " should probably be replaced with \\x20 to allow x-modifier usage without side-effects. --Danwe (talk) 01:40, 19 February 2012 (UTC)