fix(doc): simple typo (centreon#8336)

doc/en/exploitation_guide/Real_time_action.rst

@@ -43,7 +43,7 @@ The following window appears:
 .. image :: /images/guide_exploitation/acknowledged.png
  :align: center
 
-* If the **Sticky** box is checked, the acknowledgment will be maintained in case of a change of Not-OK status (E.g.: DOWN to REACHABLE or WARNING to CRITICAL). Otherwise, the acknowledgment disappears and the notification process is reactivated.
+* If the **Sticky** box is checked, the acknowledgment will be maintained in case of a change of Not-OK status (E.g.: DOWN to UNREACHABLE or WARNING to CRITICAL). Otherwise, the acknowledgment disappears and the notification process is reactivated.
 * If the **Notify** box is checked, a notification is sent to the contacts linked to the object to warn that the incident on the resource has been acknowledged (in the situation the contact possesses the activity acknowledgment notification filter).
 * If the **Persistent** box is checked, the acknowledgment will be maintained in the case of a restart of the scheduler. Otherwise, the acknowledgment disappears and the notification process is reactivated.
 * The **Comment** field is generally used to provide the reason of the acknowledgment, it is mandatory