A tagging system makes sense if you think of the whole system as a collection of completely independent notes. You create a note, you add the tags, you search for tags to find what you want. But it doesn't make as much sense if you consider the notes to be related to each other. Suppose you're writing a book, and you've got one note per chapter, and the chapters themselves are further divided into a note per section. Now you want a note that collects up all the subnotes for the chapter, and a note that collects up all the chapters into a book, and the whole thing tied together with an integrated table of contents. To mimic this with tags you can create a tag called "My Book" with subtags "Chapter 1", "Chapter 2", etc, and you just use the tags as your navigator. It's not exactly the same as a neatly *integrated* table of contents within the book itself, but it sorta works. But now what happens if you want the book itself to have a tag? You can tag a note, but you can't tag a tag. Tags are also problematic in that they are always alphabetical, so if you want any kind of custom ordering, I guess you'd have to number them. I just don't think tags alone are good for organizing related material that is stored in separate notes.