The Yonomicon is a yoyo instructional book by Mark McBride that, according to its web page [1], is "written mainly to satisfy the burning question left unanswered by all other yoyo books: Okay, now what?".
Released in 1998, it was at its publication the state-of-the-art in yo-yo trick books, not only breaking down and modularizing some of the leading-edge freestyle tricks of the day, but also providing an expressive calculus for describing tricks in shorthand form, something McBride refers to as "TFY Transcription". (TFY short for Throwhand, Freehand and Yo-Yo.)
The book is written in a witty, wizardy style and contains copious diagrams illustrating individual trick holds and moves. Among players it is still considered the de-facto standard for yo-yo trick books.