This means you need to know enough already just to get it to come up, and more to prune out the other 500 results if your term is generic enough. Basically, the search only really works if you want to find a specific conversation you remember (and it better be recent, given how easily you forget the specifics of things as time passes)
For the past couple years it's returned variations of words, eg: `installer` will return `installers`, `installed`, `installs`, `installing`. However it doesn't return synonyms. It's essentially just searching like one would with regular chat logs, except limited to searching only one server at a time.
I actually wish I could disable such matching since even with double quotes I can't get only an exact word matched (which is necessary when trying to filter a large number of results).