Notation	Name	Description	Status
1	Eye visible on radar scope, accuracy good (within 10 km)		stable
2	Eye visible on radar scope, accuracy fair (within 30 km)		stable
3	Eye visible on radar scope, accuracy poor (within 50 km)		stable
4	Position of the centre within the area covered by the radar scope, determination by means of the spiral-band overlay, accuracy good (within 10 km)		stable
5	Position of the centre within the area covered by the radar scope, determination by means of the spiral-band overlay, accuracy fair (within 30 km)		stable
6	Position of the centre within the area covered by the radar scope, determination by means of the spiral-band overlay, accuracy poor (within 50 km)		stable
7	Position of the centre outside the area covered by the radar scope, extrapolation by means of the spiral-band overlay		stable
10	Accuracy undetermined		stable
15	Missing value		stable