Current status of quark-gluon plasma signals

Compelling evidence for the creation of a new form of matter has been claim ed to be found in Pb+Pb collisions at SPS. We discuss the uniqueness of oft en proposed experimental signatures for quark matter formation in relativis tic heavy ion collisions. It is demonstrated that so far none of the propos ed signals like J/psi, meson production/suppression, strangeness enhancemen t, dileptons, and directed flow unambiguously show that a phase of deconfin ed matter has been formed in SPS Pb+Pb collisions. We emphasize the need fo r systematic future measurements to search for simultaneous irregularities in the excitation functions of several observables in order to come close t o pinning the properties of hot, dense QCD matter from data.