Morita equivalence classes of 2‐blocks with abelian defect groups of rank 4.

We classify all 2‐blocks with abelian defect groups of rank 4 up to Morita equivalence. The classification holds for blocks over a suitable discrete valuation ring as well as for those over an algebraically closed field. An application is that Broué's abelian defect group conjecture holds for all blocks under consideration here. [ABSTRACT FROM AUTHOR]