Generally, this is controlled by the praMultiSelect attribute of the property editor. So, some specific properties, which have specialized property editors can be hidden when several objects are added. One example of such kind of properties is TComponent.Name.
Okay, trying to build a demo project I recognized that I registered an own property editor for "TMyString". It seems that this is the reason why TMyString property is not shown if I select more than one objects.
Comments