In the at least one indication writing portion, {HEAD ~ regions} made of magnetic material spaced by magnetically blank portions are provided so as to define {TAIL ~ a code} which can be detected by a magnetic reading head 
In the at least one indication writing portion , { HEAD ~ regions } made of magnetic material spaced by magnetically blank portions are provided so as to define { TAIL ~ a code } which can be detected by a magnetic reading head
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH