  A group is called capable if it is a central factor group. We consider the
capability of nilpotent products of cyclic groups, and obtain a generalization
of a theorem of Baer for the metabelian small class case. The approach is also
used to obtain some recent results on the capability of certain nilpotent
groups of class 2. We also prove a necessary condition for the capability of an
arbitrary p-group of class k, and some further results.
