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