Wiki article here.
The Book of Nod is a collection of ancient texts, viewed as sacred to Noddist Cainites, who study Caine and Enoch, though the interpretations vary between the Sabbat and the Gehenna Cult.
The book contains writings and fragments about the myth of Caine and various texts, having many authors and editors over thousands of years since the events described within. Some consider the entire books to be simply myth or straight lies - stories invented by vampires to explain existence or manipulate others into thinking a certain way, while others believe it to be scripture, and many thoughts in between.
The Camarilla denounces Noddist lore and persecutes those who spread it, with any found pieces either destroyed or stashed away by powerful vampires. Despite this renouncement, it’s sought by Kindred who may wish to debunk it or those that may think there are half or full truths and prophecies of the future within it.