| Name | Data Type | Definition | |
|---|---|---|---|
| nilReason | NilReasonEnumeration | ||
| FT | string | Feet. | Inherited from UomDistanceVerticalType |
| M | string | Meters. | Inherited from UomDistanceVerticalType |
| FL | string | Flight level in hundreds of feet. | Inherited from UomDistanceVerticalType |
| SM | string | Standard meters (tens of meters). | Inherited from UomDistanceVerticalType |
| OTHER | string | Other | Inherited from UomDistanceVerticalType |