Once each requirement is passed through these tests you can evaluate and freeze the functional requirements. What will be your requirement satisfaction criteria?
In other words, this is a continuous process which happens throughout the project cycle.
For example, the site cannot determine your email name unless you choose to type it.
Allowing a website to create a cookie does not give that or any other site access to the rest of your computer, and only the site that created the cookie can read it.
Within the business analysis community, the debate still reigns about whether how the application will look and how the screens will be laid out is technically part of requirements or design. The right question is “When is the most effective time to introduce visual prototypes into your requirements process? I’ve worked on teams where the user interface wireframes or prototypes, coupled with some textual rules, formed the main body of functional requirements.
I’ve also worked on teams where the prototypes were thrown away or merely used to capture representative screen shots.