  Predictions for light charged hadron production data in the current
fragmentation region of deeply inelastic scattering from the H1 and ZEUS
experiments are calculated using perturbative Quantum Chromodynamics at
next-to-leading order, and using fragmentation functions obtained by fitting to
similar data from $e^+ e^-$ reactions. General good agreement is found when the
magnitude $Q^2$ of the hard photon's virtuality is sufficiently large. The
discrepancy at low $Q$ and small scaled momentum $x_p$ is reduced by
incorporating mass effects of the detected hadron. By performing quark tagging,
the contributions to the overall fragmentation from the various quark flavours
in the $ep$ reactions are studied and compared to the contributions in $e^+
e^-$ reactions. The yields of the various hadron species are also calculated.
