|Well, congrats. You discovered it. You get to name it.|
Although this article is based on canonical information, the actual name of this subject is conjectural.
Its contents were written using a very obscure Latinate to describe a supernatural dimension most commonly known as Purgatory. It depicted the place as filled with blood, bone, and darkness. It also contained a ritual, or as Bobby described it, an "instruction manual", on how to open Purgatory, specifically to let Eve, the Mother of All, crossover into Earth.
It was in possession of dragons during their preparation for the crossing of Eve from Purgatory. Sam and Dean retrieved it from the sewers where the dragons were hiding. They then gave it to Bobby to find out its translated contents. It was never mentioned since and would easily have been destroyed when Bobby's house was burnt.