Summarising, given the notions of netlet and loadable code, it is possible to associate application-specific behaviour with particular (sets of) netlets. Netlets and loadable code together enable applications to implement any resource allocation and management policy within the MCA domain that suits their environment. Note that the loadable code is also able to create new netlets (if need be recursively), which it can control itself as separate netlets, or associate with a DLA other than itself. Our experience with the loadable code feature of the Sandman has shown that it is extremely useful in prototyping and testing. It makes it easier to try out new operations, algorithms and policies (modifying them on the fly if need be), as they are running in a stable MCA. We will demonstrate next how it can be used for implementing interoperability between multiple MCA domains as well as for establishing global policies.