There are many special objects. You can specify which of them to display and which not. And whether crucial objects should be locked to changes. In menu click Tools->Options and select Editor tab. In order to take effect reload the object tree.
Editor options
In menu click Tools->Options and select Object tree tab. In order to take effect reload the object tree.
Object tree display options
Many pdf objects are compulsory or must contain required entries or have specified values. Incompetent manipulation with these objects can result in invalid pdf files or non predictable output. Therefore a mode is assigned to every property which indicates the importance of the property. There are
Unknown - mode not known
Normal - normal property, editing should not harm
Hidden - not crucial property, editing should not harm
Read only - not property, manual editing does not make sense
Advanced - crucial property, incompetent editing can make harm
When mouse cursor is over a property the property mode is displayed as text in the status bar. Hidden, read only and advanced tincture property colour to blue, gray and red. It depends on the theme used.
Visualization of object mode
These settings are stored in mode.conf file which can be easily modified to match user own pdf skills.