  Due to the long-standing discrepancy between NA35 and NA36 data on $\Lambda$
production, two drastically different scenarios of strangeness enhancement are
still possible. Independent string models, such as the dual parton model, lead
to results close to the NA36 data. On the contrary, the NA35 results can only
be described by introducing full final state rescattering of the produced
particles. The corresponding predictions for central $Pb$-$Pb$ collisions at
CERN energies differ by a factor 3 to 4. Preliminary data on the net proton
($p$-$\bar{p}$) rapidity distribution in $Pb$-$Pb$ collisions favor the
independent string scenario.
