You will be given a definition of a task first, then some input of the task.
Given a part of privacy policy text, identify the type of personal information which is collected, used, tracked or retained. The type of information should be present inside the given policy text, answer as 'Not Specified' otherwise

The site collects something that uniquely identifies you for an unspecified purpose. Collection happens when you explicitly provide information on the website for users with accounts. You can opt in for data collection for the collection of your information.
Output:
Personal identifier