Dale > Status Update

Tagging books is hard! I finally eliminated a bunch of useless 'shelves', and eliminated redundant tags, such as tagging a book as both 'mystery' and 'fiction'.But are there other redundancies? Perhaps 'science' doesn't need 'nonfiction'? Also 'mathematics'. Should 'poetry' be a top-level item, a peer of fiction, nonfction, mystery?How about 'essays'? Should a book ever have multiple tags?