Checks rules (8)
I believe the answer is:
controls
I believe this is a double definition.
'checks' is the first definition.
(controlling is a kind of checking)
'rules' is the second definition.
('control' can be a synonym of 'rule')
(Other definitions for controls that I've seen before include "Directs or operates" , "Regulates" , "Runs" , "Directs, governs" , "Manages the regulatory mechanisms" .)