The following is included in the Requirements Document, which is one of the outputs of Collect Requirements process of Scope Management Knowledge Area in PMBOK:

Business requirements - higher level needs of org as a whole, (business issues or opportunities), and reasons why project has been undertaken.

Stakeholder requirements - needs of a stakeholder or stakeholder group.

Solution requirements - features, functions, characteristics of product, service, result that will meet business & stakeholder requirements:

Functional requirements - behavior of product (action, process, data, interactions)

Nonfunctional requirements - environmental conditions or qualities required for product to be effective (reliability, security, performance, safety, supportability)

Transition Requirements - temporary capabilities (data conversion, training) needed to transition from current state to desired future state

Project Requirements - actions, processes, conditions project needs to meet (milestone dates, contractual obligations, constraints)

Quality requirements - criteria to validate completion of project deliverables or fulfillment of other project requirements (tests, certifications, validations)