The SettlementBase attribute SettlementCenter is a enum of two options, EuroclearBank or ClearstreamBankingLuxembourg. The use of enums for this purpose is not necessary and actually more complicated to match settlement parties to a specific enum. Instead there should be settlement parties with various roles needed to support the settlement process. The proposal is to deprecate SettlementCenter and add settlementParty Party(0..) and settlementRole(0..) with the option to reference the parties on the trade.