I am happy to introduce Jmaxxz Deet. The Deet assembly contains a single struct, NotNull. This struct provides a mechanism to formally specify that a reference can NEVER be null. This ability is present in both Spec# and Sing#. However, for those of us still making use of VB, C#, F# and other traditional .Net languages still do not have a mechanism to do so. NotNull brings this capability to all of those languages.