| Tag | Field Name | XML Name | Data Type | Union Datatype | Description | Added | Depr. | Enums from tag | Valid values |
|---|---|---|---|---|---|---|---|---|---|
| 459 | UnderlyingSecurityAltIDSource | @AltIDSrc | String |
Identifies class or source of the UnderlyingSecurityAltID (458) value. Required if UnderlyingSecurityAltID is specified. Valid values: Same valid values as the SecurityIDSource (22) field | FIX.4.3 |
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