What does "by the book" mean?

In a manner which strictly adheres to rules, legal requirements, or official procedures.

By the book

Common synonyms include: according to hoyle, correctly, formally, more procedural, most textbook-based, official memo.

prep_phrase

prep_phrase ·Rare ·Advanced level

Prep_phrase

1
In a manner which strictly adheres to rules, legal requirements, or official procedures. idiomatic
"As far as he is concerned, he umpired by the book."
2
In a manner which appears too studied, ritualized, and therefore artificial. broadly, idiomatic
"Romeo: Sin from thy lips? O trespass sweetly urged! Give me my sin again. They kiss again. Juliet: You kiss by th' book."

"As far as he is concerned, he umpired by the book."