It's an Index. So, where is the book (or library) it is an index for? Say, a book of "summoning spells" - this book gives the names and pronunciation, the other book tells you what to do with the names. If Albion doesn't know about book#2, then the Index would seem like just a 'list of the names of god'.
The other historical index I can think of is the index of forbidden books. Though I don't think the Spierarch would be calm about someone creating all this mess to get a list of the evuls.
Also, I thought the warriors were halfbloods because they are "half" cat. Cat eyes, coughing roar, high body temperature, etc etc. The cats are either being metaphorical or they actually were the source of some warrior DNA.
