By tinkering around (reverse engineering is not allowed :) I found out the following:

Simple search

A simple search does an advanced search hidden from prying users eyes, which is simply quite clever. It's a "wrapper" for the advanced search, making it easy to use.

Advanced search

Roger's made quite a flexible system for the advanced search.

Fields:
artist (string)
genre (string)
tracknr (number)
comment (string)
genre (string)
year (number)
skipped_count (number of times you skipped the track with 2.x player software)
play_count (number of times the track was played with 2.x player software)
marked (string, "" is unmarked, "yes" is marked)
codec ("mp3", "wma", "wav")
copyright (number, 0 is no copyright, 1 is copyrighted)

numeric operators
<
>
<=
>=
=
!=
string operators
is (excact search)
like (glob search, example to find Various Artists): artist like "V*A*")
contains (what it says, must contain a sub-string)

and
or

You can also use ( and ) to group expressions.

Examples:

(artist is "U2") and (genre contains "rock")
year <= 1974
codec != "mp3"
marked = "yes"


There's probably more hidden in the search system, but here's what I could figure out in 30 minutes.

Have fun!


Lars