SctiesSttlmTxModReq
                Mandatory
                ModfdTxDtls
                Mandatory
                UpdTp
                Repetition (1..3)
                Addtn
                Choice
                Deltn
                Choice
                Mod
                Choice
                SttlmTpAndAddtlParams
                Optional
                Lnkgs
                Repetition (0..n)
                TradDtls
                Optional
                FinInstrmId
                Optional
                FinInstrmAttrbts
                Optional
                QtyAndAcctDtls
                Optional
                SttlmQty
                Optional
                DnmtnChc
                Optional
                AcctOwnr
                Optional
                SfkpgAcct
                Optional
                BlckChainAdrOrWllt
                Optional
                CshAcct
                Optional
                SfkpgPlc
                Optional
                SfkpgPlcFrmt
                Optional
                LEI
LEI
                Optional
                Definition: Legal entity identification as an alternate identification for a place of safekeeping.
Type: LEIIdentifier (String)
Restrictions:
- Pattern: [A-Z0-9]{18,18}[0-9]{2,2}
QtyBrkdwn
                Repetition (0..n)
                SttlmParams
                Optional
                StgSttlmInstrDtls
                Optional
                DlvrgSttlmPties
                Optional
                RcvgSttlmPties
                Optional
                CshPties
                Optional
                SttlmAmt
                Optional
                OthrAmts
                Optional
                OthrBizPties
                Optional
                AddtlPhysOrRegnDtls
                Optional
                SplmtryData
                Repetition (0..n)