In this seminal paper, we sketch a general conceptual framework for self-organising systems (SOSs) that encompasses both stigmergy and MAS coordination, and potentially promotes models of self-organisation for MASs where interaction between cognitive agents is mediated by the environment, by means of artifacts provided by the agent infrastructure. Along this line, we first introduce the notions of <em>Behavioural Implicit Communication</em> (BIC) as a generalisation of stigmergy, and of <em>shared environment</em> (s-env) as a MAS environment promoting forms of observation-based coordination (such as BIC-based ones) that exploit cognitive capabilities of intelligent agents to achieve MAS self-organisation.