Although the API also allows you to implement different cascading schemes, your applications should only implement those schemes that can be compared to a regular File System mount, as follows.
When calling the CascadingServiceMBean.mount operation, always use a non null targetPath. The target path can be assimilated to a target mount point in the File System analogy.
Never use a targetPath under which MBeans are already registered in the target MBean server. Using such a target path could cause a name conflict when mounting the source MBeans to the target MBean server.
Never give the same targetPath to two different mount operations. Like in the file system analogy, you should not attempt to mount two sources to the same target path.
The present implementation does not enforce those rules, but applications that are concerned with naming consistency and coherency should make sure to respect them.