Searching is case-insensitive, partial match search. Leading or trailing spaces in your criterion
will be removed.
But space(s) between words are important.
For example: if you specify search criterion 'us open',
- find "US Open" (case insensitive)
- find "US OPENING" (case insensitive; partial match)
- not find "open us" (different phrase)
- not find "us   open" (different number of spaces between words)
The relationship among search items
are mathematical AND
. So the more items you
specify, the less you will find.