A unique track identifier stored as UUID. The lost elevation in meters from the previous to the current TrackPoint. Only used in GPX. The gained elevation in meters from the previous to the current TrackPoint. Only used in GPX. Horizontal accuracy in meters of the current TrackPoint; 68% chance that the actual location is within this radius around the measured location. Only used in GPX. Vertical accuracy in meters of the current TrackPoint; 68% chance that the actual location is within this radius around the measured location. Only used in GPX. User-defined translation of GPX's ]]>. Only used in GPX.