When I wrote CVS requesting their coupon policy, this is the response I received:
I am in receipt of your email regarding our coupon policy. Unfortunately, I can’t send you a copy of our policy because that is proprietary information. If you have any question regarding our coupon policy and/or procedures you may contact our Customer Relations Dept at 1.800.746.7287.
So ah…yeah. If you ever need to call their number, there it is.