diff --git a/mod/forum/lib.php b/mod/forum/lib.php
index 45b450bcf35..1c91e8d8b2c 100644
--- a/mod/forum/lib.php
+++ b/mod/forum/lib.php
@@ -3191,6 +3191,10 @@ function forum_print_post_end($post, $return = false) {
 
 /**
  * Print a forum post
+ * This function should always be surrounded with calls to forum_print_post_start
+ * and forum_print_post_end to create the surrounding container for the post.
+ * Replies can be nested before forum_print_post_end and should reflect the structure of
+ * thread.
  *
  * @global object
  * @global object
diff --git a/mod/forum/upgrade.txt b/mod/forum/upgrade.txt
index b34d16eafb8..8a41ccf8cd0 100644
--- a/mod/forum/upgrade.txt
+++ b/mod/forum/upgrade.txt
@@ -1,6 +1,9 @@
 This files describes API changes in /mod/forum/*,
 information provided here is intended especially for developers.
 
+=== 3.6 ===
+  * forum_print_post should be surrounded with calls to forum_print_post_start and forum_print_post_end to create the proper HTML structure for the post.
+
 === 3.4 ===
   * External function get_forum_discussion_posts now returns an additional field "ratinginfo" containing rating information.