This is a read-only operation code for a PSG port creation-table entry, where 1 means create a new PSG port, 2 means delete a current PSG port, and 3 means switch between the active and standby port. An admin reads this to see what operation was last recorded against a given PSG port row, since despite the operational vocabulary this object itself is read-only rather than settable. For example, seeing psgPortOper report switch(3) for an entry would tell an admin an active/standby switchover was the last recorded operation on that PSG port.