The MISE Project (Mediation Information System Engineering) aims at providing virtual enterprises with a Mediation Information System (MIS) in charge of supporting interoperability in a collaborative network. MISE proposes an overall MIS design method according to a model-driven approach, based on model transformations. This MIS is in charge of (i) information management, (ii) services sharing and (iii) behavior orchestration. Semantic issues are accompanying those objectives: How to deal with information reconciliation? How to ensure the matching between business activities and technical services? How to identify workflow among business process? This article aims first, at defining these semantic gaps along the whole MISE approach. The second part of this article presents how some specific solutions have been found in the specific context of crisis management (French funded project ISyCri). Finally, the current and future works concerning semantic reconciliation (in a generic non " 1 to 1 " context) will be introduced.