Community Standards

What are the community standards of the Miller test? Is there a list of what is considered patently offensive on each community? Are previous cases conclusive as to what is patently offensive? Say, a prosecutor brings charges against material depicting graphic penetration, and cites other previous cases where graphic penetration was found to be patently offensive as evidence these new materials are also patently offensive. Would these previous cases cited in this hypothetical prove conclusive of the community standards? Or are they just a guide and at the end the jurors must draw from their own understanding?