The following Figure shows some of the subclasses of the Request entity.<br/>A DisputedAmount represents a request by an external party (Customer or Supplier/Partner) to change the amount it is required to pay the enterprise. CustomerDisputedAmount is a type of DisputedAmount which represents an amount of money in dispute between the enterprise and one of its customers.<br/>An InquiryRequest is a request for information such as a request for information about a statement of money owed by a customer.(CustomerBillingInquiry), or about a written record of goods or services provided and the amount charged for them, sent to a Customer as a request for payment (CustomerInvoiceInquiry) or any request for information from a Customer (CustomerInquiry).<br/>A Command is a Request that cannot be refused.  Any failure to service the Command as expected is treated as an exception, meaning something is wrong and needs to be fixed.<br/>