1. A method comprising: generating by a computing device an order message for a first order to buy or sell a tradeable object at an electronic exchange, wherein the first order is generated by a first application in response to detecting a fill of a second order; inserting by the computing device an order descriptor identifier into the generated order message, wherein the order descriptor identifier comprises data that defines an association between the first order and the fill of the second order, and wherein the order descriptor identifier is accessible by a second application that is different from the first application; and sending by the computing device the order message comprising the order descriptor identifier to the electronic exchange.