Edit the selected Unique Indentifier
Name		This name should contain letter, digits, hyphens or underscores only. It has to concisely describe the type of identifier. E.g. "payroll", "student_id", "lib_number" etc.
Type		Select primary if you intend to use this unique identifier when you create new users. E.g. "payroll_id" for setting up staff. A secondary unique identifier is used to help you find existing users of the system. E.g. "library_no" for searching by library number.
User Category		Select the categories of people who can be identified with this new unique identifier. (E.g. only staff can be identified with a payroll number.)