| Tag | Field Name | XML Name | Data Type | Union Datatype | Description | Added | Depr. | Enums from tag | Valid values |
|---|---|---|---|---|---|---|---|---|---|
| 539 | NoNestedPartyIDs | (not used in FIXML) | NumInGroup |
Number of NestedPartyID (524), NestedPartyIDSource (525), and NestedPartyRole (538) entries | FIX.4.3 |
|