Bring peeled, diced potatoes to a boil in a large stock pot; cook approximately 5 minutes or until just tender (you don't want mashed potatoes). Immediately drain and rinse several times in cold water to stop the cooking process; drain and put into large mixing bowl. Add next 7 ingredients and mix until thoroughly combined; adjusting amounts of relish, mayo and mustard to suit your taste. You want it to be creamy, but not too soupy. Adjust seasonings and place potato salad in a large, covered storage container; dust top with paprika and parsely leaves if desired. Refrigerate several hours before serving.