Traditional reliable broadcast protocols fail to scale to large settings [13, 1]. This paper proposes a reliable multicast protocol that integrates two recent approaches to deal with the large-scale dimension in group communication protocols: gossip-based probabilistic broadcast [2] and semantic reliability [10]. The aim of the resulting protocol is to improve the resiliency of the probabilistic protocol to network congestion by allocating scarce resources to semantically relevant messages.Although intuitively it seems that a straightforward combination of probabilistic and semantic reliable protocols is possible, we show that it offers disappointing results. Instead, we propose an architecture based on a specialized probabilistic semantically reliable layer and show that it produces the desired results. The combined primitive is thus scalable to large number of participants, highly resilient to network and process failures, and delivers a high quality data flow even when the load exceeds the available bandwidth.We present a summary of simulation results that compare different protocol configurations. The details of the simulation model are given in the full version of the paper [12] which presents the evaluation of different implementation policies and the study of relevant system parameters in the performance of the protocol.