Once a DLL stream handler is installed in the system, the stream handler must call the Sync/Stream Manager to register its entry point. After this, the Sync/Stream Manager knows the entry point address for the stream handler, specifically the SHC entry point. Therefore, the stream handler must pass the entry point address to the Sync/Stream Manager on the register call. In addition, when SMH_REGISTER is issued, the stream handler informs the Sync/Stream Manager whether it can be a source or target stream handler. The Sync/Stream Manager, in turn, returns the stream handler IDs for future interaction with the Sync/Stream Manager. The stream handler uses this ID to identify itself whenever calling the Sync/Stream Manager so it will know which stream handler is actually calling it. If a NULL stream handler is being registered, both the source and the target HID are returned as the same HID. Also, the REGISTER_NONSTREAMING bit flag must be set for NULL stream handlers. The stream-handler name can be a maximum of 8 characters in length to allow device-driver stream handlers to use their device names as the stream-handler name.