• Obsolescence is defined on a class per class basis.
• A obsolescence condition is an OQL expression, using any field of the class, including those of type AttributeExternalField
• Obsolescence condition are inherited from parent classes, but can be redefined on a child class.
• If no obsolescence condition is defined on a class and none of its parent, then objects of that class are never considered as obsolete.

        <obsolescence _delta="redefine">
          <condition><![CDATA[status='inactive']]></condition>
        </obsolescence>

        <obsolescence _delta="redefine">
          <condition><![CDATA[status='inactive' OR ISNULL(status)=1]]></condition>
        </obsolescence>

Based on object status:

   <classes><class id="Organization"><properties><obsolescence><condition>
        <![CDATA[status = 'inactive']]>
   </condition></obsolescence></properties></class><classes>

Based on object status combined with status of a parent if parent exists :

   <classes><class id="Hypervisor"><properties><obsolescence><condition>
        <![CDATA[status = 'obsolete' OR (server_id != 0 AND server_id_obsolescence_flag)]]>
   </condition></obsolescence></properties></class><classes>

Combination of status and delay:

   <classes><class id="Ticket"><properties><obsolescence><condition>
       <![CDATA[operational_status='closed' AND (close_date < DATE_FORMAT(DATE_SUB(NOW(), INTERVAL 15 MONTH),'%Y-%m-%d 00:00:00') OR (ISNULL(close_date) AND last_update < DATE_FORMAT(DATE_SUB(NOW(), INTERVAL 15 MONTH),'%Y-%m-%d 00:00:00')))]]>
   </condition></obsolescence></properties></class><classes>