A method of fabrication and a magnetic transducer having an inverted write element with a zero delta in pole tip width to provide improved bi-directional control over write track width and written erase bands on media. In one aspect, the system detects a request to copy a file from a first data storage device to a second data storage device, determines one or more parameters of the copied file, the first data storage device and the second data storage device, selects, based on the one or more parameters, a file encryption policy for the copies file, and applies the selected encryption policy to the copied file. Once a Service Provider is chosen, a pop-up window will appear telling that User if the Service Provider is available. Thus, even if the assist controlled variable exhibiting an abnormal value is computed for some reason, the abnormal value of the assist controlled variable is limited to an appropriate value corresponding to each signal value by the final limits. The streams may exist on a shared or independent PID.