diff --git a/src/wp-admin/includes/upgrade.php b/src/wp-admin/includes/upgrade.php
index 32e8d2c6a2..32d853cb05 100644
--- a/src/wp-admin/includes/upgrade.php
+++ b/src/wp-admin/includes/upgrade.php
@@ -1749,6 +1749,7 @@ function upgrade_330() {
 			$sidebars_widgets                   = $_sidebars_widgets;
 			unset( $_sidebars_widgets );
 
+			// intentional fall-through to upgrade to the next version.
 		case 2:
 			$sidebars_widgets                  = retrieve_widgets();
 			$sidebars_widgets['array_version'] = 3;
diff --git a/src/wp-admin/post.php b/src/wp-admin/post.php
index 6f95adc17e..c932d72e18 100644
--- a/src/wp-admin/post.php
+++ b/src/wp-admin/post.php
@@ -205,6 +205,7 @@ switch ( $action ) {
 
 		wp_update_attachment_metadata( $post_id, $newmeta );
 
+		// Intentional fall-through to trigger the edit_post() call.
 	case 'editpost':
 		check_admin_referer( 'update-post_' . $post_id );
 
diff --git a/src/wp-admin/user-edit.php b/src/wp-admin/user-edit.php
index 3a469a3db0..cfcce8f66a 100644
--- a/src/wp-admin/user-edit.php
+++ b/src/wp-admin/user-edit.php
@@ -173,6 +173,7 @@ switch ( $action ) {
 			exit;
 		}
 
+		// Intentional fall-through to display $errors.
 	default:
 		$profileuser = get_user_to_edit( $user_id );
 
diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
index 4d39696eb7..118d563cda 100644
--- a/src/wp-includes/general-template.php
+++ b/src/wp-includes/general-template.php
@@ -655,6 +655,7 @@ function get_bloginfo( $show = '', $filter = 'raw' ) {
 					'<code>url</code>'
 				)
 			);
+			// Intentional fall-through to be handled by the 'url' case.
 		case 'url':
 			$output = home_url();
 			break;