 Further to this; letters on shoulders will denote borough or newly formed basic command units and not the police station an officer is based from.An example of this would be a PC working from East Ham Police Station in the borough of Newham; the PC would have KF (Newham) on their shoulder and not KE (East Ham station).Similarly in newly merged boroughs a PC working from Holloway Police Station would have CN (Central North BCU) on their shoulder.