+

A leading plus sign indicates that this word must be present in every match returned.

-

A leading minus sign indicates that this word must not be present in any match returned.

< >

These two operators are used to change a word's contribution to the relevance value that is assigned to a match. The < operator decreases the contribution and the > operator increases it. See the example below.

( )

Parentheses are used to group words into subexpressions.

~

A leading tilde acts as a negation operator, causing the word's contribution to the match relevance to be negative. It's useful for marking noise words. A match that contains such a word will be rated lower than others, but will not be excluded altogether, as it would be with the - operator.

*

An asterisk is the truncation operator. Unlike the other operators, it should be appended to the word, not prepended.

"

The phrase, that is enclosed in double quotes ", matches only items that contain this phrase literally, as it was typed.

And here are some examples:

apple banana

find matches that contain at least one of these words.

+apple +juice

... both words.

+apple macintosh

... word "apple", but rank it higher if it also contain "macintosh".

+apple -macintosh

... word "apple" but not "macintosh".

+apple +(>pie <strudel)

... "apple" and "pie", or "apple" and "strudel" (in any order), but rank "apple pie" higher than "apple strudel".

apple*

... "apple", "apples", "applesauce", and "applet".

"some words"

... "some words of wisdom", but not "some noise words".