Client wants to have a field displayed in CA1 ISPF in order to know on which CPUID the tape has been created. In the case that the TMC file is shared between several partitions the current CPUID field is updated each time that the tape is opened for input or output.
To store the CPUID on which a tape has been created you need to code the TMOKEYxx to obtain the CPUID and store it in the ACCT field. You can also use TMSXITJ and TMSXITC to obtain and store the CPUID in the ACCT field. This is the only place to store the information and have it stay static during the life of the tape data set.