Section I of the book contains an explanation of the concept of transparency as it is understood in the context of international investment agreements. Section II provides a review of current treaty and arbitral practice with respect to transparency issues. Section III analyses the interaction of transparency obligations with other related issues. The final section of this paper contains a series of policy options available to IIA negotiators and those involved in revising arbitral rules. In this final section, the paper also briefly discusses the implications of those options for host State development considerations so as to assist with negotiator decision-making on whether or not to include transparency provisions in IIAs, and, if so, which formulation to insert into new agreements.