Book tag?

Hello lovely people…

Anybody here knows what a book tag is? Another blogger left a comment on my blog saying that they wanted to do a book tag with me, before I agree to it, I’d like to know what they mean! 🙂 (Matters are not helped by the fact that the person in question is a Spanish speaker and my Spanish is still not as good as I’d like it to be! Nevertheless she did use the phrase ‘book tag’ in English.)