diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index d165af2..566a19c 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -951,10 +951,13 @@ function drupal_static_reset($name = NULL) {
 /**
  * Formats text for emphasized display in a placeholder inside a sentence.
  *
- * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
- *   Note this this method should not be used to only emphasise a string and
- *   therefore has few valid use-cases. Note also, that this method does mark
- *   the string as safe.
+ * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0. Use
+ *   \Drupal\Component\Utility\SafeMarkup::format() and a %variable in
+ *   associative array of replacements to make instead. Note this this method
+ *   should not be used to only emphasise a string and therefore has few valid
+ *   use-cases. Note also, that this method does not mark the string as safe.
+ *
+ * @see \Drupal\Component\Utility\SafeMarkup::format()
  */
 function drupal_placeholder($text) {
   return '<em class="placeholder">' . Html::escape($text) . '</em>';