What is uncontrolled logging policy? I am reading Learning from Logged Implicit Exploration Data 

It says 


  Formally, given a dataset of the form S = (x, a, r_a)* generated by the interaction of an uncontrolled logging policy


What is such a policy?
This policy is usually referred to as the Behaviour Policy when talking about off-policy learning. It is the policy that actually takes actions in the world. The policy that one wants to learn, such as a greedy policy in Q learning, is know as the target policy. In this way the behaviour policy “logs” experience that the target policy (or policies) may learn from.