The Elko field of Ahluwalia and Grumiller is a quantum field for massive spin-1/2 particles. It has been suggested as a candidate for dark matter. We discuss our attempts to interpret the Elko field as a quantum field in the sense of Weinberg. Our wo
rk suggests that one should investigate quantum fields based on representations of the full Poincare group which belong to one of the non-standard Wigner classes.
