The Initiative for Policy Dialogue (IPD) refers to this document as the project charter.
In customer relationship management (CRM), it is known as the project definition report.
Both IPD and CRM require this document as part of the project management process.
Developing the charter and identifying the stakeholders are the two main actions of the initiating process group.
The project manager will work with the key stakeholders (customers and business sponsors), the PMO, Subject Matter Experts inside and outside the organization, other units within the organization and may also work with Industry groups or professional bodies to develop the charter.