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