One can only "prepend" something before some other thing, not "append".

include/options/compose.php

@@ -123,7 +123,7 @@ function load_optpage_data_compose() {
 
     $optvals[SMOPT_GRP_COMPOSE_REPLY][] = array(
         'name'    => 'sig_first',
-        'caption' => _("Append Signature before Reply/Forward Text"),
+        'caption' => _("Prepend Signature before Reply/Forward Text"),
         'type'    => SMOPT_TYPE_BOOLEAN,
         'refresh' => SMOPT_REFRESH_NONE
     );
@@ -185,4 +185,4 @@ function save_option_reply_prefix($option) {
     save_option($option);
 
 }
-?>
+?>