This data setup are used to define the outflow condition features. The outflow geometry is restricted to rectangular/line forms in 3D/2D configuration. In the particular case of cylindrical geometries, the outlets can be circular, annular or bowed rectangular. In fact, the geometry of the outlet fits the grid topology.
&Outlet_Boundary_Conditions Type_of_BC= "OUTLET", Direction_Normal_Plan= 1 , Plan_Location_Coordinate= -0.05 , Start_Coordinate_of_First_Span = -0.01, End_Coordinate_of_First_Span = 0.01, Start_Coordinate_of_Second_Span= 0.0 , End_Coordinate_of_Second_Span= 0.0 , Pressure_Reference_Value = 0.0 , Length_Scale = 1.0 , Flow_Direction= 1 , End_of_Data_Block= .true. /
Find some examples here about outflow configurations.