Ethical Walls in Contracts

In the past I’ve worked on contracts that have ethical or Chinese walls where one or more potential bidders are already carrying out work with the organisation. Usually it’s to make sure that the existing work goes smoothly without any potential advantage being given to one party in the new tender and there’s often a requirement for a separate bid team for the supplier and strong rules around what can and cannot be talked about. I don’t have access to wording for this now. Does anyone have anything they can share? Or point me in the direction of some instruction?