He caters for people who don't follow rules (8)
I believe the answer is:
cheaters
'people who don't follow rules' is the definition.
'cheaters' can be an answer for 'people' (cheater is a kind of person). I'm not certain of the rest of the definition.
'he caters' is the wordplay.
'he caters' can be anagrammed to 'CHEATERS'.
Though, I'm unsure how this is indicated.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for cheaters that I've seen before include "Teachers for swindlers" , "Deceivers, swindlers" , "who flout the rules" .)