Definition
Charts not compiled on WGS84 carry a caution giving the adjustment in seconds or fractions of a minute of latitude and longitude to be applied to satellite-derived positions before plotting. The shift is stated with its direction, for example positions should be moved 0.05 minutes south and 0.09 minutes east. Where the survey is old or the shift is unquantified, the note may instead warn that the shift cannot be determined, and the chart must then be used with extra caution.
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