5.13.1 A bearing scale around the periphery of
the operational display area should be provided. The bearing scale
should indicate the bearing as seen from the consistent common reference
point.
5.13.2 The bearing scale should be outside of
the operational display area. It should be numbered at least every
30° division and have division marks of at least 5°. The 5°
and 10° division marks should be clearly distinguishable from
each other. 1° division marks may be presented where they are
clearly distinguishable from each other.