# description
A component of an aviation itinerary such as a flight segment, ground transport leg, or ancillary service.

# properties.elementType.description
Type of itinerary element (FLIGHT, GROUND_TRANSPORT, ANCILLARY)

# properties.segmentRef.description
Reference to a flight segment if this is a flight element

# properties.legRef.description
Reference to a transport leg if this is a surface element

# properties.sequence.description
Sequential order of this element within the itinerary