I know you can search for "type:bible", for example to list just bibles, and I found a video tutorial that said you could search for "-lang:greek" to exclude greek resources. But where is this comprehensively documented? When I saw the "type:bible" example the first time, I naively assumed you could search for values in any of the columns in the library listing. However "languages:greek" doesn't work. It's spelled "lang", but nowhere can I find any documentation that that is the case, just forum posts and videos mentioning it in passing.
Are there other things that can be specified? Other syntax that's evidently a closely guarded secret? (LOL).