Not sure if these are NSI specific questions, or general NML questions. All relate to Port/PortGroups and use of labels. 1. I can have a Port without a Label, and a PortGroup without a LabelGroup. In this case the Port id alone uniquely identifies the resource. 2. Can i have a Label or LabelGroup specified with a label type but no value? In this case the Port is identified uniquely by id and label type. 3. Can I have Ports/PortGroups with different label types grouped in the same SwitchingService or are they restricted to having the same labeltype? 4. If I can have Ports/PortGroups with different label types in the same SwitchingService, then does a value of labelSwapping == true means I can swap between different labeltypes as well? If we do permit different label types in the same SwitchingService then adding a labelType attribute to the SwitchingService would need to have additional behaviour defined to restrict label swapping to only ports with labels of that type. Thanks, John.