Crossword Genius

Strictly according to the rules (2,3,4)

Ross

I believe the answer is:

by the book

(Other definitions for by the book that I've seen before include "According to the rules" , "Strictly following rules" .)

I've seen this clue in The Guardian and the Sydney Morning Herald.
Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.