The program has opened the standard labeled tape data set to read it backwards, but the last specified volume for the standard labeled data set ends with EOV labels. When a standard labeled tape data set is opened to read it backward, the system expects the last volume in the list of volumes associated with the data set to end with EOF labels.
The system calls the label anomaly installation exit routine. The installation exit provided by IBM takes no action, and therefore the system ignores the condition. The label anomaly exit of your installation might cause the system to issue ABEND 637 rc B4 and message IEC026I.
This is either an error, an intentional action by the user, or the tapes are from another operating system. If you have a system automation product that can distinguish between a user error and the other causes, you may be able to configure that product to correct the error or to cancel or stop the job. DFSMSrmm can correct the volume list.
Possible error. Check whether the volumes on the DD statement or the dynamic allocation are complete and in the correct order.