diff --git a/src/wp-includes/link-template.php b/src/wp-includes/link-template.php
index 58366208b1..0cbf6ac799 100644
--- a/src/wp-includes/link-template.php
+++ b/src/wp-includes/link-template.php
@@ -1961,6 +1961,7 @@ function adjacent_posts_rel_link( $title = '%title', $in_same_term = false, $exc
  * or theme templates.
  *
  * @since 3.0.0
+ * @since 5.6.0 No longer used in core.
  *
  * @see adjacent_posts_rel_link()
  */