Change in autocomplete behavior on wikitech and mw.org
The default autocomplete profile has been changed to include sub phrase
matching. Essentially this means the autocomplete matching can start at
various points within the page title, rather than only at the very start.
This has shown to be particularly useful on sites with long or nested page
titles like mw.org and wikitech.
This is only the default, if you don't enjoy the new behaviour it can be
changed back to the default profile (or other, stricter profiles) from the
Special:Preferences Search tab.