The Project Line Clearance value (PLCL) can be measured from the Angular Dimension's origin or from the position defined by a DPPT or DPOI. The PLCL is controlled by the PLCLFLag attribute on DPPT and DPOI elements. By default this is False (or OFF) in which case the clearance is measured from the Dimension's origin. If PLCLFL is set True (or ON) the clearance is measured from the position defined by the DPPT or DPOI. The example illustrates the two Dimension Directions.