Rules and punishment at school (5)
I believe the answer is:
lines
I believe this clue is a double definition.
'rules' is the first definition.
(I've seen this in another clue)
'punishment at school' is the second definition.
'and' is the link.
(Other definitions for lines that I've seen before include "Skin wrinkles" , "writing done by pupil?" , "imposition" , "old-fashioned school punishment" , "Marks" .)