"Paginarum Fulvarum"

Also known as the Liber Paginarum Fulvarum (Latin for "Book of Yellow Pages") or Necrotelecomnicon, this book is a shared joke between Gaiman and fellow author Terry Pratchett.

It also appears in Pratchett's Discworld series and the book Good Omens, which was co-authored by Pratchett and Gaiman. The Necrotelecomnicon of the Discworld is a list of all the old, dark gods, and this Paginarum Fulvarum seems to have the same function.