Requirements are an inventory of events, conditions, or functions that need to be satisfied and tracked by an application.
Requirements are described in various forms. Some are non-functional while others articulate specific business rules that must be satisfied. While requirements can be typed directly into the specification description itself, if requirements can be shared by multiple specifications, a best practice is to separate the requirements into individual ones and associate them with the related specifications.
Typically, requirements are specified in the Application Profiler, and included in the application generated by the Application Accelerator as Application Requirements. You can update the requirements in the application itself as a project evolves.
They also are referenced in application rules, Specification rules, and flows.
For details about working with requirements, see the PDN articles listed under the Direct Capture of Objectives section of the Implementation Methodology knowledge category.