All I want to do is eliminate .wma and similar files, just as it is possible to eliminate "adult content" for results of my searches. Soon after I first learned of LimeWire, I downloaded an audio file of a rather obscure song (purportedly) that turned out to contain an embedded link to a porn site. That set off a chain of links to about a dozen related sites before I was able to close everything down. So I am paranoid about those file types, and don't want to even have them presented to me. It seems that most of the titles in which I have a special interest have been returned as available ... in .wma form ... and in my excitement at finding the rarity, I have clicked on the download for them. Then I really looked at the file being downloaded, and realized that I wanted no part of it ... ad cancelled the download.

With the varied ways in which people store their files, it would take 2*n-1 different search arguments to specify only the .mp3 forms of a song title. (Since any of the n words in the search argument could be found next to the file type.) Just how difficult could it be to apply the same filter we can specify in "files to be shared" to "files to be searched"?

Perhaps you are implying that ¬ may work? At least, that is the mathematical symbol for NOT, and would make sense ... or !shall?