So far, we have focussed on solutions of SDEs where we are simply given a filtration, and with it the Brownian motion W and the random measure μ. We then construct the solution to our equation ( 17.2). In essence, we have used no properties of the filtration except the fact that W and μ are adapted. As we shall see, there are occasions where this approach is insufficient, and we require that the filtration is slightly richer.