I should probably set up a topic-tag for the LHMP for books that are intended either as textbooks or general reference works (e.g., encyclopedia-type texts) because I'm starting to get a number of them and it seems like a category that people might find useful. Not sure how to handle that, because it doesn't really fit with the types of tags I already have set up. But, hey, I can just add it to the "topics" list and sort it out later if I decide to do it differently.