  By a regular embedding of a graph K in a surface we mean a 2-cell embedding
of K in a compact connected surface such that the automorphism group acts
regularly on flags. In this paper, we classify the nonorientable regular
embeddings of the Hamming graph H(d,n). We show that there exists such an
embedding if and only if n=2 and d=2, or n=3 or 4 and d>0, or n=6 and d=1 or 2.
We also give constructions and descriptions of these embeddings.
