The first four discussed below, namely ACK, RST, SYN, and FIN are used in the establishment, maintenance, and tear-down of a TCP connection. 

Often a contract writer might wish to customize the behavior of the contract for some customers and not others. For thes e binary cases,

we recommend the use of account flags. Flags are stored against individual Payment Devices, Accounts, and Customers. They are a Boolean

piece of state that allows us to control the flow of a contract

Example use cases for flags include:

Marking a customer account as delinquent because they stopped paying their bills.

Adding a repayment holiday flag to an account so the customer doesn't have to repay their bill on time.

Flagging a customer as dormant when they stop using their product, leading to a freeze on the account.

Tier based features such as a better deal for employees, to help with staff retention.