Despite having wrapped up the "Harry Potter" saga with her last novel, author J.K. Rowling has decided to delve into the Harry Potter world one more time to write the definitive reference book on the subject, reports TV Guide.

On her website, Rowling confirmed that she’s working on the long-rumored "Harry Potter Encyclopedia."

Rowling wrote: "For a long time I have been promising an encyclopedia of Harry’s world, and I have started work on this now — some of it forms the new content in Pottermore [the online ‘Harry Potter’ site]. It is likely to be a time-consuming job, but when finished I shall donate all royalties to charity."

Rowling also notes on her website that she has never said “never” to the question of whether there might eventually be another “Potter” novel — although she reiterates that she has no immediate plans to write one.