you implemet in code interface Eco.LinkOperationCache.IMultiLinkCatcher that has the only method MultiLinkModified(IAssociationEnd ae). Within the method you can implement some handling for one or more multiroles of your class. Important: the method will be fired *after* a multirole changes, i.e. some objects have been added to or removed from the other association end.

  public partial class MyClass : Eco.LinkOperationCache.IMultiLinkCatcher
  {
      #region IMultiLinkCatcher Members
      void Eco.LinkOperationCache.IMultiLinkCatcher.MultiLinkModified(IAssociationEnd ae)
      {
          if (ae.LoopbackIndex == Eco_LoopbackIndices.MyMultilinkProperty1)
          {
               DoSomething1;
          }

          else if (ae.LoopbackIndex == Eco_LoopbackIndices.MyMultilinkProperty2)
          {
               DoSomething2;
          }

      }
      #endregion
............................
  }

/Efim