OK, it mostly works, but I was looking for an old post about modeling many-to-many relationships. So I enter "many-to-many" (with and without the quotes) and get no result. Yet, the post does exist. It's Ben's comment on this post: http://community.thoughtworks.com/posts/45eb71b1e0
The Author search criterion is case-sensitive. Putting "ben" or "ben butler-cole" in it in addition to "many" in the keyword field returns no result. Replacing it with "Ben" does.