Bellcore's preliminary view of the basic security features required that should be provided by an Operating System and its associated services, i.e., features required of an Operating Environment. These requirements are generic and are not specific to any particular Operating Environment. They provide baseline requirements that can be made more specific to a particular Standard Operating Environment. In addition to addressing Operating Environment features, this document also provides requirements on the Operating Environment vendors to develop, document, package and maintain their product in a fashion that will not denigrate the security features.