  The description of longitudinal photons is far from trivial, and their
phenomenological importance is largely unknown. While the cross section for
direct interactions is calculable, an even more important contribution could
come from resolved states. In the development of our model for the interactions
of (real and) virtual photons, we have modeled resolved longitudinal effects by
simple multiplicative factors on the resolved transverse-photon contributions.
Recently, a first set of parton distributions for longitudinal virtual photons
has been presented by Ch\'yla. We therefore compare their impact on some
representative distributions, relative to the simpler approaches.
