There is a wide agreement on the use of norms in order to specify the expected behaviour of agents in open MAS. However, current norm formalisms focus on the declarative nature of norms. In order to be implemented, these norms should be translated into operational representations. In this paper we present our preliminary work on implementation of norm enforcement and issues on verifiability that highly affect this enforcement. We propose some mechanisms to be included in agent platforms in order to ease the implementation.