Deregulation data

Hi,

Can anyone help me understanding the way we can use the deregulation data in terms of billing ?

I'm mainly interested in better understanding the impacts of the following fields:

- "Invoicing service provider" (EVER-INVOICING_PARTY) and "Payment class" (EVER-SERVPROV_PAY) defined on the contract

- "Bank payment method" (FKKOP-ETHPPM), Payment frequency" (FKKOP-PAYFREQID), "Invoicing service provider" (FKKOP-INVOICING_PARTY) defined on the FI-CA document

How to deal with those fields in a:

- one-contract model ?

- two-contract model ?

Thanks in advance for your help.

Sébastien