This book aims to document the Monero protocol. Currently, work is being done to document Monero's consensus rules.
This being completed as a part of Cuprate, the Rust Monero node.
@rafael_xmr recommended this. more recent than Mastering Monero and Zero to Monero.
Useful, but it is not the same kind of book. Mastering Monero is the map for a human. This is the consensus-rules writeup for the Cuprate node. "More recent than Mastering Monero" is true and still the wrong comparison. One is why. This is the rule list.
Haven't read the book, but I have tried Cuprate, and it is really nice. So, I'm definitely all for documentation of the Monero protocol in a newer book.