diff -u b/core/lib/Drupal/Component/Utility/SafeMarkup.php b/core/lib/Drupal/Component/Utility/SafeMarkup.php
--- b/core/lib/Drupal/Component/Utility/SafeMarkup.php
+++ b/core/lib/Drupal/Component/Utility/SafeMarkup.php
@@ -170,11 +170,11 @@
    * @ingroup sanitization
    *
    * @deprecated Will be removed before Drupal 8.0.0. Rely on Twig's
-   *   auto-escaping feature, or, use the '#plain_text' key when constructing a
-   *   render array that contains plain text in order to use the renderer's
-   *   auto-escaping feature. If neither of these are possible,
-   *   \Drupal\Component\Utility\Html::escape() can be used in places where
-   *   explicit escaping is needed.
+   *   auto-escaping feature, or use the @link theme_render #plain_text @endlink
+   *   key when constructing a render array that contains plain text in order to
+   *   use the renderer's auto-escaping feature. If neither of these are
+   *   possible, \Drupal\Component\Utility\Html::escape() can be used in places
+   *   where explicit escaping is needed.
    *
    * @see drupal_validate_utf8()
    */