The P parameter

Specifying ",P" with the "S=" and "X=" commands sets a flag in the device entry that prevents its manipulation by the ALL specification. Refer to the example below:

F ATAM,X=500,P    *Device 500 permanently excluded
F ATAM,S=501,P    *Device 501 permanently selectable
F ATAM,S=ALL      *Make all devices selectable, except device 500
F ATAM,X=ALL      *Exclude all devices from ATAM, except device 501
F ATAM,S=500      *Make device 500 selectable and reset "permanent" flag 
F ATAM,X=501      *Exclude device 501 and reset "permanent" flag 

When you specify the “P” parameter with the “S” command, the ATAM device status displays as follows:

ATH041I SYSA TAPE LIST: 0500+SF 0501+SF 0502+SF 0503+SF

The plus (+) between the device number and “SF” indicates that the device is permanently assigned and will not be processed as part of a S=ALL or X=ALL command.

You cannot specify the “P” parameter with any other “S” command parameters, such as “U” or “F”.