My hunch is this is a duplicate request, but I haven't run into it, so here goes.
I found the Boolean features for URL searches very helpful but saw no documentation about all its features. Is it hidden somewhere? Finally I ran into this answer. For example, I discovered the minus sign is used instead of NOT.
Does it make sense for these explanations to be placed in a FAQ, or somewhere visible? I like it because I can easily bookmark various filters and send a link to others. Or is it better to keep URL searching informal and hidden?