Finite rank Butler groups and torsion-free modules over a discrete valuation ring

Fully faithful functors from isomorphism at p categories of finite rank But ler groups to torsion-free modules of finite rank over the integers localiz ed at a prime p are constructed via categories of representations of antich ains over discrete valuation rings. Descriptions and properties of modules in the images of these functors are given, including a characterization of finite representation type and a complete list of indecomposables in that c ase.