Shadows are "aliases" for objects. Both WPProgram and WPFileSystem objects can be "shadowed" but it is not recommended to make shadow copies of programs. This is because a user might mistakenly edit the program title of the shadow copy and change the original program's filename, thus preventing it from being executed.
The behavior of a shadow is identical to the object it shadows in all respects except one; deleting a shadow does not affect the source object. In practice, the user may find other differences; for example, deleting an object causes the deletion of all its shadows. Shredding an object which has shadows linked to it will generate a message window, informing the user that this object has shadows associated with it.
Distinguishing a shadow icon from an object icon can be difficult, as there is only a subtle visual distinction between objects and their shadows (the text of a shadow is "grayed" or "dimmed"). Some users find it difficult to distinguish such a subtle difference and they should modify the shadow color text using the Scheme Palette within the System Setup folder. Shadows are also differentiated from real objects by the presence of the "Original" choice at the bottom of their context menus.