If you are unfamiliar with this document, do not be vexed. A functional specification document (fsd), also known as a functional requirements document (frd), is considered by many project management and software. An frd defines the specific functions and features that the. Documenting the functional requirements provides several important benefits to the organisation and to the process of developing a solution. This document is a functional requirements document (frd) template that outlines the sections and content needed for documenting software requirements.