ISO 6709

ISO 6709 is defines the representation of geographic point locations (latitude, longitude, altitude) by coordinates.

A point is defined by

• two mandatory values for the horizontal coordinate (for example latitude and longitude)
• an optional vertical value (height, depth)
• an optional identification of the spatial reference system (SRS).

Rules:

• Latitude before longitude (same as EPSG:4326)
• North latitude and east longitude is positive
• In digital data exchange, fraction of degrees are preferred (while sexagesimal notation is tolerated).