SEGW: Howto set subscribable with vocablary based annotations?

Hi,

according to http://help.sap.com/saphelp_gateway20sp08/helpdata/en/41/c49c527bf4487a842295263e01d9ad/content.htm one can set Subscribable on an entity set and then the appropriate coding is supposed to be generated. However this checkbox seems not to be available when using vocabulary based annotations. So how do I set subscribable with vocablary based annotations?

Thanks in advance,

Wolfgang