This made me realize I have a poor sense of the features in search, so I
read the documentation.
http://www.mediawiki.org/wiki/Help:Searching is bare-bones, and
https://en.wikipedia.org/wiki/Help:Searching disagrees. Perhaps the former
describes the default MediaWiki search features, while WMF has enabled more
and different features on its wikis (such as intitle: and incategory:
searches).
* mw help doesn't mention the * suffix to search for partial matches, or
the ~ prefix. Both work on my unmodified local wiki.
* enwiki says "Hello dolly" in quotes gives different results, mw directly
contradicts this. Even on my local wiki, quotes make a difference.
* enwiki disagrees with itself what a dash in front of a word does.
I fixed mw search's explanation of the two-button search box (no longer the
default) but I don't know the details on the above.
--
=S Page software engineer on Editor Engagement Experiments