Index: wp-admin/includes/class-wp-automatic-updater.php
===================================================================
--- wp-admin/includes/class-wp-automatic-updater.php	(revision 45005)
+++ wp-admin/includes/class-wp-automatic-updater.php	(working copy)
@@ -648,18 +648,18 @@
 
 		switch ( $type ) {
 			case 'success': // We updated.
-				/* translators: 1: Site name, 2: WordPress version number. */
+				/* translators: Site updated notification email subject. 1: Site name, 2: WordPress version number. */
 				$subject = __( '[%1$s] Your site has updated to WordPress %2$s' );
 				break;
 
 			case 'fail':   // We tried to update but couldn't.
 			case 'manual': // We can't update (and made no attempt).
-				/* translators: 1: Site name, 2: WordPress version number. */
+				/* translators: Updated available notification email subject. 1: Site name, 2: WordPress version number. */
 				$subject = __( '[%1$s] WordPress %2$s is available. Please update!' );
 				break;
 
 			case 'critical': // We tried to update, started to copy files, then things went wrong.
-				/* translators: 1: Site name. */
+				/* translators: Site down notification email subject. 1: Site name. */
 				$subject = __( '[%1$s] URGENT: Your site may be down due to a failed update' );
 				break;
 
@@ -911,10 +911,10 @@
 			);
 			$body[] = '';
 
-			/* translators: Background update failed notification email subject. %s: site title */
+			/* translators: Background update failed notification email subject. %s: Site name */
 			$subject = sprintf( __( '[%s] Background Update Failed' ), $site_title );
 		} else {
-			/* translators: Background update finished notification email subject. %s: site title */
+			/* translators: Background update finished notification email subject. %s: Site name */
 			$subject = sprintf( __( '[%s] Background Update Finished' ), $site_title );
 		}