Can I filter for all photos not in an album?

Hey All,

I can't seem to figure out how to filter for all photos I've not added to an album. I want to clean up everything I've not categorised.

I vaguely remember doing this is the past, I even had my workflow built around it, but now if I type 'album:' in the search bar it only shows me my 'shared albums' but not the ability to select 'no albums' (or even my own albums for that matter.

Does anyone have any help?

PS. Also, Lightroom seems to completely lack any real documentation apart from the very limited 'user guide'. And it's mad that for such an expensive piece of software thate is no support.