Carbon and credits
Project design document
A project design document, often called the PDD, describes a carbon project and shows how it applies its methodology: the location, the activities, the baseline, additionality, the boundary, the monitoring plan and the expected credits. It is checked by an independent validator before the project can register.
It is the promise the project is later held to. Each monitoring report is verified against what the PDD said would be measured and how.
A thorough PDD takes effort up front and saves it later, because a monitoring plan that was clear from the start is easy to follow and easy to verify.