You are creating a new legacy variant business unit.

 The SAP Customer Data Platform preconfigures matching rules to ensure accurate customer data matching. These rules are applied sequentially; if no match is found using the first identifier, the next identifier is tried. The predefined matching rules include:

Match Customers based on masterDataId

Match Customers based on crmId

Match Customers based on ciamId

This setup helps in identifying and matching customer data accurately for both the Contextual Profile view and the Unified Profile view.

References = The information is verified and matched with the details provided in the SAP Customer Data Platform documentation and learning resources12.