We revise multiset rewriting with name binding, by combining the two main existing approaches to the study of concurrency by means of multiset rewriting: multiset rewriting with existential quantification and constrained multiset rewriting. We obtain nu-MSRs, where we rewrite multisets of atomic formulae, in which some names may be restricted. We prove that nu-MSRs are equivalent to a class of Petri nets in which tokens are tuples of pure names, called p nu-APNs. Then we encode pi-calculus processes into nu-MSRs in a very direct way, that preserves the topology of bound names, by using the concept of derivatives of a pi-calculus process. Finally, we discuss how the recent results on decidable subclasses of the pi-calculus are independent of the particular reaction rule of the pi-calculus, so that they can be obtained in the more general framework of nu-MSRs. Thus, those results carry over not only to the pi-calculus, but to any other formalism that can be encoded within it, as p nu-APNs.