BuyInRgltryAdvc
                Mandatory
                Account Owner
AcctOwnr
                Optional
                Definition: Party that legally owns the account.
Type: PartyIdentification144
Mandatory
                LEI
                Optional
                SfkpgAcct
                Mandatory
                BuyInAttrbts
                Repetition (1..n)
                SplmtryData
                Repetition (0..n)