These are legitimate page title names, no need for the software to block them.

If a local wiki doesn't want them, an AbuseFilter or entry to the page title blacklist are more appropriate. Marking WONTFIX.

Where they're syntactical elements of a search query they really should be excluded from the search suggestion.

• Bug 21137 has been marked as a duplicate of this bug. ***

rainman wrote:

*** Bug 21467 has been marked as a duplicate of this bug. ***

This also happens with the ~ and - prefixes, and the * suffix.

MediaWiki:Searchmenu-new is also a bit ugly: '''Create the page "[[:$1]]" on this wiki!''' I understand the bold, but the exclamation mark? While at it, if this bug is fixed the message can be made a bit more encouraging, like «'''You can create the page "[[:$1]]" on this wiki.'''» (such a wording would currently make the effects of this bug worse); the bug 27311 could make the link more helpful and always valid whatever the permissions/processes on the wiki.

7rt1j wrote:

As mentioned on bug 29989, this is also the case with double quotes used in search phrases.

• Bug 29989 has been marked as a duplicate of this bug. ***

We actually did this with Cirrus. If other backends support fancy syntax and want to do the same, they can too by returning true in SearchResultSet::searchContainedSyntax() implementations.