[walk the chalk] or [walk the chalk line] or [walk the chalk mark] To act exactly as you are supposed to; behave properly; obey.
* /That new teacher really makes the students walk the chalk./* /In some classes the students play and talk, but Mr. Parker makes them walk the chalk./* /That theater owner wants his place to be orderly, and if boys and girls don't walk the chalk, he puts them out./
(From the fact that sailors used to be asked to walk a chalk line along the deck of the ship to prove they were not drunk.) Compare: TOE THE MARK.