  An outer bound to the capacity region of the two-receiver discrete memoryless
broadcast channel is given. The outer bound is tight for all cases where the
capacity region is known. When specialized to the case of no common
information, this outer bound is contained in the Korner-Marton outer bound.
This containment is shown to be strict for the binary skew-symmetric broadcast
channel. Thus, this outer bound is in general tighter than all other known
outer bounds on the discrete memoryless broadcast channel.
