  Let $\mathcal{V}$ be a congruence permutable variety generated by a finite
nilpotent algebra $\mathbf{A}$. If $\mathbf{A}$ is a product of algebras of
prime power order, then the class $\mathcal{V}_\text{si}$ of subdirectly
irreducible members of $\mathcal{V}$ can be axiomatised by a finite set of
elementary sentences.
