| Name | Data Type | Definition | |
|---|---|---|---|
| nilReason | NilReasonEnumeration | ||
| ENR | string | En-route holding. | Inherited from CodeHoldingUsageBaseType |
| TER | string | Terminal area holding. | Inherited from CodeHoldingUsageBaseType |
| OTHER | string | Other. | Inherited from CodeHoldingUsageBaseType |