It contains two parts: one showing information for zones and another for objects. These parts work independent of each other. When objects are selected at the same time as a zone, you will see link information for both (see Figure 4cc below). 
Figure 4: The Add-On palette is shown above in different stages depending on what elements are currently selected: a) a single zone that is not linked b) single or multiple object(s) that are not linked c) a zone and object that are both linked d) multiple objects that have different link statuses
It shows a 'Room Number' and a 'Room Name' attributes of the room that the currently selected zone is linked to. For objects it shows the 'Item Number' and 'Name' attributes of an article that the objects are linked to. If a zone or an object is not linked, its status will be "Not linked" (Figure 4a, 4ba and b) and a 'Link' button will be enabled. Read more about linking and unlinking zones and objects in Linking zones and Linking ArchiCAD objects to Items in Section 4.1 and Section 5.1.dRofus.
If there are none or multiple zones selected at the same time, the top part of the palette shows nothing (Figure 4aa), because only one zone can be linked to a room in dRofus. The same happens with the items section when the current selection does not contain any objects (Figure 4bb). Unlike zones, multiple objects can be linked to a single item in dRofus. If selected objects are linked to the same item, their link info will be shown on the palette. But if they are linked to different items or some of them are not linked, you will see the message shown in Figure 4dd.