  We prove configuration results for extremal Type II codes, analogous to the
configuration results of Ozeki and of the second author for extremal Type II
lattices. Specifically, we show that for $n \in \{8, 24, 32, 48, 56, 72, 96\}$
every extremal Type II code of length $n$ is generated by its codewords of
minimal weight. Where Ozeki and Kominers used spherical harmonics and weighted
theta functions, we use discrete harmonic polynomials and harmonic weight
enumerators. Along we way we introduce "$t\frac12$-designs" as a discrete
analog of Venkov's spherical designs of the same name.
