Dev:CFKeyedArchiverUID

CFKeyedArchiverUID is the "8th property list object" for supporting NSKeyedArchiver. It is essentially a 32-bit integer, but this specific type is used to denote a link in the object graph.

This type will appear as &lt;NSCFType 0xXXXXXXXX&gt; when NSLog-ing it, which is not useful. Apple's Property List Editor does not recognize this type, so if you edit a plist generated by NSKeyedArchiver, data will be lost.