BuyInRgltryAdvc
                Mandatory
                AcctOwnr
                Optional
                Mandatory
                LEI
LEI
                Optional
                Definition: Legal entity identification as an alternate identification for a party.
Type: LEIIdentifier (String)
Restrictions:
- Pattern: [A-Z0-9]{18,18}[0-9]{2,2}
SfkpgAcct
                Mandatory
                BuyInAttrbts
                Repetition (1..n)
                SplmtryData
                Repetition (0..n)