A hidden function not mentioned in the keyboard shortcuts documentation (at least in the minimal install version) is the F3 key song search. It's very useful when I have a long playlist, and I want to find a particular song. A dialog box appears for me to type in a searach query. When I choose a search result, it automatically plays it. However, sometimes I just want to select a song and not play it. This has the benefit of not interrupting the current song, and for me to edit/rearrange the list item (maybe move the song in the playlist to be played next in the queue.)
In short, a way to "select" and not "play" a search result. Since F3 command seems to be undocumented, maybe this functionality is already implemented?