provide expire feature on post and comments as well as private messages. This requires a feature setting and is currently unmaskable - if the author says it's gone, there's not a lot you can do to stop it or try and save it. It's gone.

mod/editlayout.php

@@ -129,6 +129,9 @@ function editlayout_content(&$a) {
 		'$preview' => ((feature_enabled(local_user(),'preview')) ? t('Preview') : ''),
 		'$jotplugins' => $jotplugins,
 		'$sourceapp' => t($a->sourcename),
+		'$defexpire' => '',
+		'$feature_expire' => 'none',
+		'$expires' => t('Set expiration date'),
 	));
 
 	$ob = get_observer_hash();