A volume's internal and external labels must be identical when the mount is for a non-specific volume. If the labels are not equal or unavailable (no label, uninitialized, etc.), then different recovery actions are taken depending on the mode of operation. If the tape library is in automatic mode, then the system will:

• Create an internal label if the tape is uninitialized or unlabeled.
• Reject the tape if the internal label is unreadable and RACF Tape Volume Protection is active.

If the tape library is in automatic mode, but the external label is unreadable, then the system will:

• Create an internal label if the volume is uninitialized.
• Reject the volume if the internal and external labels are unequal, unlabeled, or unreadable, and RACF Tape Volume Protection is active.

If the tape library is in manual mode, then it will:

• Create an internal label if the volume is uninitialized or unlabeled.
• Issue WTOR IEC704A if the internal and external labels are unequal. The operator can supply the external label or reject the volume.
• Reject the volume if the internal label is unreadable and RACF Tape Volume Protection is active.

If the volume label is extracted from the VOLID MARK and an installation option allows its use in either automatic or manual mode, then the external label is used to verify the volume. The system uses the external label to verify the volume if all of the following are true:

• A higher formatted cartridge is mounted on a drive in response to an output request and that drive does not fully support that recording format.
• OPEN or EOV is able to read the VOLID mark.
• The OPEN or EOV volume label editor installation exit routine allows this relabelling.
• The user has RACF UPDATE authority to the volume.
• The DEVSUP member of SYS1.PARMLIB specifies VOLNSNS=YES.