I know it's random, but I sit in a coffee shop and up on the shelf is The Dictionary of Synonyms. At first I thought "Why not call it a Thesaurus." The I realized that a thesaurus is a compilation of synonyms and antonyms.
So now my issue isn't the mis-labeling of the book, but instead the apparent lack of need of it. Why would anyone choose a compilation of synonyms over a thesaurus that supplies both synonyms and antonyms? Hopefully, The Dictionary of Synonyms is way cheaper than a thesaurus, or perhaps came with a companion volume of antonyms.