This Part 3 of the standard specifies the requirements for the overall functionality and engineering services to achieve building automation and control systems. It defines terms, which shall be used for specifications and it gives guidelines for the functional documentation of project/application specific systems. It provides a sample template for documentation of plant/application specific functions, called BACS points list in annex A. The informative function block examples explain a method to display the referenced functions in system documentation; they do not standardize the method for programming functions and applications. This part of the standard