F indicates that the volume on the device for the input/output data set is file protected. That is, its file protection ring is not inserted or its tab is set to prevent a write, so it can only be read.
If the volume should be file protected, enter REPLY xx,‘U’.
If the volume should be written on, enter REPLY xx,‘F’; the system will rewind and unload the volume. Then insert file protection ring or move the tab in the volume, mount the volume, and ready the device.
DFSMSdfp
IGC0K05B
1,3
2