vCloud 5.1 RESTful api supports reading and updating metadata of vApps. You can save there key:value pairs and you can also specify type of the value. It is practical for example for saving/reading owner of given vApp. I have implemented two methods in vCloud driver, one for getting all metadata of given vApp and one for setting value for given vApp and key. It currently supports only string value type (we don't need typechecking there). I will attach the patch soon.