[type of data: composed data (literal); repeatable]
For terrestrial maps, give the coordinates in the following order:
- westernmost extent of area covered by item (longitude)
- easternmost extent of area covered by item (longitude)
- northernmost extent of area covered by item (latitude)
- southernmost extent of area covered by item (latitude)
Express the coordinates in degrees, minutes, and seconds of the sexagesimal system (360 degree circle) taken from the Greenwich prime meridian. Precede each coordinate by W, E, N, or S, as appropriate.
For celestial charts, give as coordinates the right ascension of the item, or the right ascensions of the western and eastern limits of its collective coverage, and the declination of the centre of the item, or the northern and southern limits of its collective coverage.