Someone is offering to teach me how to talk to cats.
“The Cat Language Bible” – sounds like future litterbox lining.
It doesn’t seem to me to be “training your cat” as much as “your cat training its human” – which cats have been doing for a very long time.
I lived with a variety of cats for long periods of time, and found they could communicate pretty well. Squatting over my shoes and peeing on them meant: I don’t like you. Standing in front of the bowl where there was no food meant “HINT. HINT.” Kicking stuff out of the litter box and onto the floor meant “I AM ALIVE AND WELL BUT I AM DISSATISFIED WITH YOUR STANDARDS OF CLEANLINESS.”