Finally, the CD specifics the rating ID, which describes the fee structure (if any) for transacting with the channel. This parameter allows for flexibility around transaction fees; for example, some channels may be billed on a "per use" fashion, while others can be charged commission, while yet others are billed a flat monthly fee. In some circumstances, it is even possible for a recipient to cover the sender's fees (e.g. a merchant covering its customer's fees). Fees are intended to be competitive with Mainnet gas fees, legacy financial system fees, and even the fees of other Layer2 solutions.