  Given a map of simplicial topological spaces, mild conditions on degeneracies
and the levelwise maps imply that the geometric realization of the simplicial
map is a cofibration. These conditions are not formal consequences of model
category theory, but depend on properties of spaces, and similar results have
not been available for any model for the stable homotopy category. In this
paper we prove such results for symmetric spectra. Consequently, we get a set
of conditions which ensure that the geometric realization of a map of
simplicial symmetric spectra is a cofibration. These conditions are very
user-friendly in that they are simple, often easily checked, and do not require
computation of a latching object or any other knowledge of Reedy theory.
