The base elements in z/OS® represent an IPLable target system and satisfy most of the dependencies of the base elements and optional features. But some elements and features require other features or IBM® products that are not part of the z/OS base. Moreover, some elements and features have optional dependencies on other features or on IBM products that help you take full advantage of z/OS capabilities. For a list of required and optional dependencies, see Software requirements for running z/OS V2R1.