Code 131 - Coded Data Field:
Cartographic materials - geodetic,
grid and vertical measurement (NR)
Indicators: blank
Subfield codes
$a Spheroid (Repeatable)
$b Horizontal Datum (Repeatable)
$c Grid and Referencing System (Repeatable)
$d Overlapping and Referencing System (Repeatable)
A two character code indicating a subsidiary grid or referencing system
which extends across the face of the cartographic material.
$e Secondary Grid and Referencing System (Repeatable)
A two character code indicating a subsidiary grid or referencing system
which appears in the form of marginal ticks.
$f Vertical Datum (Repeatable)
A two character code used to indicate the vertical datum(s) named on the
cartographic material
$g Unit of Measurement of Heighting (Repeatable)
A two character code indicating the unit of measurement of heighting
$h Contour Interval (Repeatable)
Up to four characters indicating the value of interval of the main contours
(i.e. those contours which always appear when applicable) in the unit of
measurement given in subfield $g. Up to one decimal place may be recorded
values of more than one decimal place should be rounded up to one.
Repeatable for each value when, for example, the value changes with height.
$i Supplementary Contour Interval (Repeatable)
Up to four characters indicating the value of the interval of supplementary
contours, i.e. contours used between main contours to increase the topograph
topographic expression of the area (e.g. in areas of low relief) or contours
whose value is not repeated on the surface of the map. The unit of
measurement is that given in ubfield $g. Up to one decimal place may be
recorded, values of more than one decimal place should be rounded up to one.
$j Unit of Measurement of Bathymetry (Repeatable)
$k Bathymetric Interval (Repeatable)
$l Supplementary Bathymetric Interval (Repeatable)
The oceanographic equivalent of subfields $g to $i. The rules for these
subfields apply to subfields