new <object> classes (and therefore different <object>'s child nodes).
<object_ref> node is identical to <object>, except that it does _not_ have
-"class" property and has additional required property "ref". It's concept is
+"class" property and has additional required property "ref". Its concept is
similar to Unix symlinks: value of the "ref" property is equal to the value of
"name" property of some existing node (called referred node) in the resources
(not necessary top-level). Referred node's "class" property and all subnodes