Confused – ‘data definitions and calculations’ – must be provided prior to contract?

I’m assisting a customer who is completing an RFQ to be accepted as a supplier to a major bank. One of the headings is ‘Data Quality’ and the first question is ‘Supplier will ensure data definitions and calculations are documented and agreed to ensure consistent understanding and use, this documentation will be provided prior to contract agreement’. Data definitions I think I get but calculations is not understood at all.

My client is a recruitment agency.