meson
as a function of beam energy and system size performed by the NA49 collaboration
are discussed. Hadronic transport models fail to describe the production
of multi strange particles 
, while statistical models are
generally in good agreement to the measured particle yields at all energies.
The system size dependence is well reproduced by the core-corona approach.
New data on K*(892) production are presented. The yields of these short-lived
resonances are significantly below the statistical model expectation.
This is in line with the interpretation that the measurable yields are
reduced due to rescattering of their decay products inside the fireball.
Key words: Heavy ion reactions, quark-gluon plasma, strangeness production
