Here are some good starting points for browsing.
Here's a title search. Try something like wiki or sandwich.
Use the following for a full text search. This takes a few seconds. The results will show all lines on a given page which contain a match.
In a fuzzy pages search the titles of all pages are examined to find those which are similarly spelled or similar sounding (english).
Separate words with a space. All words have to match as substrings.
'OR', grouping with parenthesis, string-quoting and some glob-style wildcard characters are also supported.
To exclude words from a title search or full text search, prepend a '-'.
Use '^xx' or 'xx*' to match words starting with 'xx'.
Use '*xx' or 'xx$' to match words ending with 'xx'.
Use '^word$' to match exact words.
Use regex=auto and 're:' like 're:word.*xx' or regex=posix to use posix regular expressions. (not yet)
Use regex=auto and '//' like '/^word$/' or regex=pcre to match using perl-style regular expressions.
Use regex=sql to match using SQL-style wildcards '%' and '_'.
Use regex=none to match any wildcards verbatim.
Example: 'wiki text -php' looks for all pages containing the words 'wiki' and 'text',
but not containing the word 'php'.