Announcement of rules — pub checks (5,2)
I believe the answer is:
reins in
'checks' is the definition.
(check can mean to control or rein in)
'announcement of rules pub' is the wordplay.
'announcement of' indicates a 'sounds like' (homophone) clue.
'rules' becomes 'reigns' (reign can mean to rule or govern).
'pub' becomes 'in' (I can't justify this - if you can you should give a lot more credence to this answer).
'reigns' sounds like 'reins'.
'reins'+'in'='REINS IN'
Can you help me to learn more?
(Another definition for reins in that I've seen is " Checks".)