UU Group Rings
A ring is called UU if each its unit is a unipotent. We prove that the group ring R[G] is a commutative UU ring if, and only if, R is a commutative UU ring and G is an abelian 2-group. This extends a result due to McGovern-Raja-Sharp (J. Algebra Appl., 2015) established for commutative nil-clean group rings. In some special cases we also discover when R[G] is a non-commutative UU ring as our results are closely related to those obtained by Ko¸san-Wang-Zhou (J. Pure Appl. Algebra, 2016) and Sahinkaya-Tang-Zhou (J. Algebra Appl., 2017).