new file:   lib/templates/admin/form/custom-companion-positioning.html

I added to help box to  Companion positioning,
Modified file diff out:
<pre>
--- /revive-adserver-master/www/admin/campaign-edit.php	2013-10-06 19:20:10.000000000 +0200
+++ /openx/www/admin/campaign-edit.php	2013-10-23 14:32:37.000000000 +0200
@@ -629,9 +629,11 @@
     $form->addDecorator ( 'h_misc', 'tag', array ('attributes' => array ('id' => 'sect_misc', 'class' => $newCampaign ? 'hide' : '' ) ) );

     //priority misc
-    $miscG['anonymous'] = $form->createElement('advcheckbox', 'anonymous', null, $GLOBALS['strAnonymous'], null, array("f", "t" ));
+    $miscA['anonymous'] = $form->createElement('advcheckbox', 'anonymous', null, $GLOBALS['strAnonymous'], null, array("f", "t" ));
+    $form->addGroup($miscA, 'misc_a', $GLOBALS['strMiscellaneous'], "<BR>");
     $miscG['companion'] = $form->createElement('checkbox', 'companion', null, $GLOBALS['strCompanionPositioning']);
-    $form->addGroup($miscG, 'misc_g', $GLOBALS['strMiscellaneous'], "<BR>");
+    $miscG['info'] = $form->createElement('custom', 'companion-positioning');
+    $form->addGroup($miscG, 'misc_g', '&nbsp;');

     $commentsG ['comments']  = $form->createElement ( 'textarea', 'comments', null);
     $form->addGroup ( $commentsG, 'comments_g', $GLOBALS['strComments'], "<BR>" );
</pre>