This paper identifies four essential principles that would enable the transparency system to build trust in collective action. Together, universality and self-differentiation set the basis for constructing a system in which all countries report on information, drawing from a menu of reporting options that allows them to do so in a way aligned with their Nationally
Determined Contributions (NDCs) and national capacities. No-backsliding helps guard against any lessening of ambition with respect to the current reporting and review requirements. In turn, continuous improvement helps ensure that ambition in the system rises over time.