diff --git a/src/wp-includes/plugin.php b/src/wp-includes/plugin.php
index baa0a585ff..5a87e40635 100644
--- a/src/wp-includes/plugin.php
+++ b/src/wp-includes/plugin.php
@@ -575,6 +575,15 @@ function remove_all_actions($tag, $priority = false) {
  * apply_filters_deprecated(), which triggers a deprecation notice and then fires
  * the original filter hook.
  *
+ * Note: the value and extra arguments passed to the original apply_filters() call
+ * must be passed here to `$args` as an array. For example:
+ *
+ *     // Old filter.
+ *     return apply_filters( 'wpdocs_filter', $value, $extra_arg );
+ *
+ *     // Deprecated.
+ *     return apply_filters_deprecated( 'wpdocs_filter', array( $value, $extra_arg ), '4.9', 'wpdocs_new_filter' );
+ *
  * @since 4.6.0
  *
  * @see _deprecated_hook()