It doesn't take a genius to understand what a voluntary tool/framework is. Like many of the NIST frameworks including the well known cyber security framework, t

It doesn't take a genius to understand what a voluntary tool/framework is. Like many of the NIST frameworks including the well known cyber security framework, these aren't mandated by NIST to be used. But that organisations globally can use the framework in uplifting or driving improved measures around privacy. If you go to the NIST website and read it, you will have all of your questions clearly answered.