FIX Algorithmic Trading Definition Language, better known as FIXatdl, is a standard for the exchange of meta-information developed in the mid-2000s to address the problems around algorithmic trading definition. An algo is driven by a series of parameters that the bank needs its customers to send in. How do you define these things? How do you convey exactly what the parameters are? What the valid values are? How should they be laid out on a particular UI section, for example? All of these elements are things that FIXatdl actually did. Its main innovation was all around the layout of the tickets, so how should it appear in the OMS?