we all know that it is a bad idea to put objects on a layer that is being workgroup referenced into a drawings because when the references are updated, the objects on a referenced layer in the target file are discarded. Most users know not to draw on a referenced layer but what has happened is that when objects are grouped and the referenced layer is current, then the grouped objects are automatically put on the referenced layer. then, when the reference is updated the information is gone. Unfortunately , it usually is the case that "show/snap/modify others" is selected so that most information can be selected and moved together and then grouped so entire files of information have been lost. Does there exist a patch that could post a message saying "you are about to transfer objects to a referenced layer. Are you sure you want to do this?"