A method for forming a magnetoresistive layer first employs a substrate over which is formed a magnetoresistive layer formed of a magnetoresistive material. A private information management apparatus receives setting data from a user terminal and creates a privacy rule that defines a condition for restricting disclosure of private information and a restriction method. Subsequently, an application layer login is sent from the first port to the second port to establish a first data path, wherein the first data path is from the first port to the second port. A difference in optical power is determined between the first optical tap and the second optical tap from the first measurement and the second measurement. These factors may include a number of times that the element has been tagged with the assigned tag and users’ votes on the accuracy of the assigned tag to the element.