The CDISC Protocol Representation Model Version 1.0 (PRM V1.0) is intended for those involved in the planning and design of a research protocol. The model focuses on the characteristics of a study and the definition and association of activities within the protocols, including arms and epochs. PRM V1.0 also includes the definitions of the roles that participate in those activities. The scope of this model includes protocol content including Study Design, Eligibility Criteria, and the requirements from the ClinicalTrials.gov and World Health Organization (WHO) registries. The majority of business requirements were provided by subject matter experts in clinical trial protocols. PRM V1.0 is based on the BRIDG Release 3.0 Protocol Representation sub-domain. It includes all classes in the BRIDG Protocol Representation sub-domain plus some classes from other BRIDG sub-domains, generally classes required for ClinicalTrials.gov and the WHO registries.