6. **ABA (American Bankers Association)**: The American Bankers Association (ABA) is a trade association representing banks of all sizes in the United States. The ABA issues routing numbers, which are used to identify financial institutions for the purpose of processing checks, electronic funds transfers, and other transactions within the United States.

7. **A2A (Account-to-Account Payments)**: Account-to-Account (A2A) Payments refer to the electronic transfer of funds from one bank account to another. This type of payment system simplifies the process by allowing direct transfers between accounts, without the need for intermediary institutions. It is commonly used for personal or business transactions both within the same bank and between different banks.

8. . **Address Verification Service (AVS)**: The Address Verification Service (AVS) is a fraud prevention system used to verify the billing address provided by a credit card holder against the address on file with the card issuer. AVS helps ensure the authenticity of transactions by comparing these addresses, and is widely used in e-commerce and online payment environments to mitigate fraud risks.