Below are options for further constraining your search terms.
You can now use Lucene query syntax, as shown here:
Lucene query syntax
Fields you can search on include
'title, body, user, tag, date, postid, sectionid'
(If you use Lucene commands, the other options here will be ignored.)
title:"hello" will return all the posts with the title "Hello"
user:"hitchhiker" will return all the posts by user 'hitchhiker'