Just a lame script to find any attributes for a given objectClass which are not used by any other objectClasses:

var a="";
var l=document.getElementsByTagName("tr");
for (var i in l)
{
	try { var m=l[i].getElementsByTagName("a"); }
	catch(e) { var m=[]; }
	if (m.length == 1)
	{
		try { var z=l[i].innerHTML.match(/^.*Used.*by.*objectClasses.*User.*Authorization.*$/); }
		catch(e) { var z=0; }
		if (z)
		{
			var p=l[i].parentNode.getElementsByTagName("tr")[0].getElementsByTagName("a");
			a += ("\""+p[0].innerHTML+"\", ");
		}
	}
}
console.log(a);