Clinical study protocols are important cornerstones on the journey of collecting the clinical data needed to elucidate the benefit-risk profile of medical treatments/devices. Not only do they lay down the plan for the study at hand, they serve as a repository of knowledge for the strategic intentions and will be used for multiple down-stream activities. They are the basis for trial registration, provide guidance to those running the study, and will be used by participants, ethics committees/institutional review boards, funders, regulators, journal editors, and systematic reviewers to appraise the study.