Duality and Weak Energy Dependence of Single-Particle Spectra

For the inclusive process, $a+b\to c+\mathrm{anything}$, it is suggested that the invariant cross section for the fragmentation of $b$ has weak energy dependence if $\mathrm{ab}\overline{c}$ or $b\overline{c}$ is an exotic channel. This is shown to follow directly from the criterion of Chan et al. that weak energy dependence is present when just $\mathrm{ab}\overline{c}$ is an exotic channel. The duality criterion for energy independence in the central region $-a\overline{c}$ and $b\overline{c}$ are exotic channels - is examined. Problems which arise from having a different duality criterion for fragmentation and central distributions are discussed.