A generic High Level Architecture (HLA) interface provides solutions for distributed simulation problems but it does not provide use patterns to guarantee universal solutions for all the simulation applications. This is one of the main disadvantages of the HLA standard: the same problem can be solved in different ways. The SISO CSPI PDG standard can be considered as the first standard developed to standardize how HLA is used to support distributed simulation. This standard proposes four Interoperability Reference Models (IRM) to identify the typical interoperability problems in manufacturing and logistics environments and to avoid possible confusions using HLA. Simulators interoperability is considered a critical capability for future joint forces. This paper proposes Interoperability Reference Models for the exclusive use of military applications, taking into account the SISO standard and the specific requirements of military environments. The types A, B, C and D of the SISO standard have been redefined, and a completely new IRM, type E, has been defined for Plan and Order Exchange situations.