When the IBObject.ObjectClass property of the IBArray is either "NSArray" or "NSMutableArray", the inner elements contains an element to indicate the XML serialization followed by the elements of the array.
Examples of XML code:
<object class="NSMutableArray" key="children"> <bool key="EncodedWithXMLCoder">YES</bool> <reference ref="601701719"/> <reference ref="334170355"/> <reference ref="1001122846"/> <reference ref="431464563"/> <reference ref="692045935"/> <reference ref="383511723"/> </object>