--- /dev/null
+<?php
+
+namespace Drupal\Core\Routing;
+
+use Symfony\Component\Routing\Route;
+
+/**
+ * A backwards compatibility route.
+ *
+ * When a route is deprecated for another one, and backwards compatibility is
+ * provided, then it's best practice to:
+ * - not duplicate all route definition metadata, to instead have an "as empty
+ * as possible" route
+ * - have an accompanying outbound route processor, that overwrites this empty
+ * route definition with the redirected route's definition.
+ *
+ * @see \Drupal\rest\RouteProcessor\RestResourceGetRouteProcessorBC
+ */
+class BcRoute extends Route {
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __construct() {
+ parent::__construct('');
+ $this->setOption('bc_route', TRUE);
+ }
+
+}