When in prison the L.O.P means Loss Of Privileges.
The L.O.P or Loss Of Privileges is a disciplinary measure by D.O.C which means taking away property such as radios, TV's Books or restricting the movement of the prisoner.
The prisoner would have to do something wrong in prison to get the loss of privileges disciplinary measure used on them.
Eventually if the prisoner does good and stays behaved they can earn their privileges back.