In order to separate RedHatEnterpriseLinux from the community product, RedHatLinux has become a community project (the FedoraProject), and the releases are now known by the name FedoraCore. FC 3 was released in November 2004, FC 2 was released in May 2004.
Fedora Core is defined as "the distribution: the package set that is included on the set of ISO images and directory tree blessed by the steering committee and released as FedoraCore. The steering committee sets policies for FedoraCore, and provides the infrastructure to build it. RedHat Network carries the core package set."
In order to distinguish FC from RedHatEnterpriseLinux, you will get "test" releases of Fedora Core rather than betas, and "updates" rather than errata.
31 pages link to FedoraCore: