diff --git a/mod/forum/deprecatedlib.php b/mod/forum/deprecatedlib.php
index 3be31b986e7..be682bd5fa4 100644
--- a/mod/forum/deprecatedlib.php
+++ b/mod/forum/deprecatedlib.php
@@ -25,474 +25,135 @@ defined('MOODLE_INTERNAL') || die();
 // Deprecated a very long time ago.
 
 /**
- * How many posts by other users are unrated by a given user in the given discussion?
- *
- * @param int $discussionid
- * @param int $userid
- * @return mixed
  * @deprecated since Moodle 1.1 - please do not use this function any more.
  */
-function forum_count_unrated_posts($discussionid, $userid) {
-    global $CFG, $DB;
-    debugging('forum_count_unrated_posts() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    $sql = "SELECT COUNT(*) as num
-              FROM {forum_posts}
-             WHERE parent > 0
-               AND discussion = :discussionid
-               AND userid <> :userid";
-    $params = array('discussionid' => $discussionid, 'userid' => $userid);
-    $posts = $DB->get_record_sql($sql, $params);
-    if ($posts) {
-        $sql = "SELECT count(*) as num
-                  FROM {forum_posts} p,
-                       {rating} r
-                 WHERE p.discussion = :discussionid AND
-                       p.id = r.itemid AND
-                       r.userid = userid AND
-                       r.component = 'mod_forum' AND
-                       r.ratingarea = 'post'";
-        $rated = $DB->get_record_sql($sql, $params);
-        if ($rated) {
-            if ($posts->num > $rated->num) {
-                return $posts->num - $rated->num;
-            } else {
-                return 0;    // Just in case there was a counting error
-            }
-        } else {
-            return $posts->num;
-        }
-    } else {
-        return 0;
-    }
+function forum_count_unrated_posts() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
 // Since Moodle 1.5.
 
 /**
- * Returns the count of records for the provided user and discussion.
- *
- * @global object
- * @global object
- * @param int $userid
- * @param int $discussionid
- * @return bool
  * @deprecated since Moodle 1.5 - please do not use this function any more.
  */
-function forum_tp_count_discussion_read_records($userid, $discussionid) {
-    debugging('forum_tp_count_discussion_read_records() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    global $CFG, $DB;
-
-    $cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;
-
-    $sql = 'SELECT COUNT(DISTINCT p.id) '.
-           'FROM {forum_discussions} d '.
-           'LEFT JOIN {forum_read} r ON d.id = r.discussionid AND r.userid = ? '.
-           'LEFT JOIN {forum_posts} p ON p.discussion = d.id '.
-                'AND (p.modified < ? OR p.id = r.postid) '.
-           'WHERE d.id = ? ';
-
-    return ($DB->count_records_sql($sql, array($userid, $cutoffdate, $discussionid)));
+function forum_tp_count_discussion_read_records() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Get all discussions started by a particular user in a course (or group)
- *
- * @global object
- * @global object
- * @param int $courseid
- * @param int $userid
- * @param int $groupid
- * @return array
  * @deprecated since Moodle 1.5 - please do not use this function any more.
  */
-function forum_get_user_discussions($courseid, $userid, $groupid=0) {
-    debugging('forum_get_user_discussions() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    global $CFG, $DB;
-    $params = array($courseid, $userid);
-    if ($groupid) {
-        $groupselect = " AND d.groupid = ? ";
-        $params[] = $groupid;
-    } else  {
-        $groupselect = "";
-    }
-
-    $allnames = get_all_user_name_fields(true, 'u');
-    return $DB->get_records_sql("SELECT p.*, d.groupid, $allnames, u.email, u.picture, u.imagealt,
-                                   f.type as forumtype, f.name as forumname, f.id as forumid
-                              FROM {forum_discussions} d,
-                                   {forum_posts} p,
-                                   {user} u,
-                                   {forum} f
-                             WHERE d.course = ?
-                               AND p.discussion = d.id
-                               AND p.parent = 0
-                               AND p.userid = u.id
-                               AND u.id = ?
-                               AND d.forum = f.id $groupselect
-                          ORDER BY p.created DESC", $params);
+function forum_get_user_discussions() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
 // Since Moodle 1.6.
 
 /**
- * Returns the count of posts for the provided forum and [optionally] group.
- * @global object
- * @global object
- * @param int $forumid
- * @param int|bool $groupid
- * @return int
  * @deprecated since Moodle 1.6 - please do not use this function any more.
  */
-function forum_tp_count_forum_posts($forumid, $groupid=false) {
-    debugging('forum_tp_count_forum_posts() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    global $CFG, $DB;
-    $params = array($forumid);
-    $sql = 'SELECT COUNT(*) '.
-           'FROM {forum_posts} fp,{forum_discussions} fd '.
-           'WHERE fd.forum = ? AND fp.discussion = fd.id';
-    if ($groupid !== false) {
-        $sql .= ' AND (fd.groupid = ? OR fd.groupid = -1)';
-        $params[] = $groupid;
-    }
-    $count = $DB->count_records_sql($sql, $params);
-
-
-    return $count;
+function forum_tp_count_forum_posts() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Returns the count of records for the provided user and forum and [optionally] group.
- * @global object
- * @global object
- * @param int $userid
- * @param int $forumid
- * @param int|bool $groupid
- * @return int
  * @deprecated since Moodle 1.6 - please do not use this function any more.
  */
-function forum_tp_count_forum_read_records($userid, $forumid, $groupid=false) {
-    debugging('forum_tp_count_forum_read_records() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    global $CFG, $DB;
-
-    $cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);
-
-    $groupsel = '';
-    $params = array($userid, $forumid, $cutoffdate);
-    if ($groupid !== false) {
-        $groupsel = "AND (d.groupid = ? OR d.groupid = -1)";
-        $params[] = $groupid;
-    }
-
-    $sql = "SELECT COUNT(p.id)
-              FROM  {forum_posts} p
-                    JOIN {forum_discussions} d ON d.id = p.discussion
-                    LEFT JOIN {forum_read} r   ON (r.postid = p.id AND r.userid= ?)
-              WHERE d.forum = ?
-                    AND (p.modified < $cutoffdate OR (p.modified >= ? AND r.id IS NOT NULL))
-                    $groupsel";
-
-    return $DB->get_field_sql($sql, $params);
+function forum_tp_count_forum_read_records() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
 // Since Moodle 1.7.
 
 /**
- * Returns array of forum open modes.
- *
- * @return array
  * @deprecated since Moodle 1.7 - please do not use this function any more.
  */
 function forum_get_open_modes() {
-    debugging('forum_get_open_modes() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-    return array();
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
 // Since Moodle 1.9.
 
 /**
- * Gets posts with all info ready for forum_print_post
- * We pass forumid in because we always know it so no need to make a
- * complicated join to find it out.
- *
- * @global object
- * @global object
- * @param int $parent
- * @param int $forumid
- * @return array
  * @deprecated since Moodle 1.9 MDL-13303 - please do not use this function any more.
  */
-function forum_get_child_posts($parent, $forumid) {
-    debugging('forum_get_child_posts() is deprecated.', DEBUG_DEVELOPER);
-
-    global $CFG, $DB;
-
-    $allnames = get_all_user_name_fields(true, 'u');
-    return $DB->get_records_sql("SELECT p.*, $forumid AS forum, $allnames, u.email, u.picture, u.imagealt
-                              FROM {forum_posts} p
-                         LEFT JOIN {user} u ON p.userid = u.id
-                             WHERE p.parent = ?
-                          ORDER BY p.created ASC", array($parent));
+function forum_get_child_posts() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Gets posts with all info ready for forum_print_post
- * We pass forumid in because we always know it so no need to make a
- * complicated join to find it out.
- *
- * @global object
- * @global object
- * @return mixed array of posts or false
  * @deprecated since Moodle 1.9 MDL-13303 - please do not use this function any more.
  */
-function forum_get_discussion_posts($discussion, $sort, $forumid) {
-    debugging('forum_get_discussion_posts() is deprecated.', DEBUG_DEVELOPER);
-
-    global $CFG, $DB;
-
-    $allnames = get_all_user_name_fields(true, 'u');
-    return $DB->get_records_sql("SELECT p.*, $forumid AS forum, $allnames, u.email, u.picture, u.imagealt
-                              FROM {forum_posts} p
-                         LEFT JOIN {user} u ON p.userid = u.id
-                             WHERE p.discussion = ?
-                               AND p.parent > 0 $sort", array($discussion));
+function forum_get_discussion_posts() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
 // Since Moodle 2.0.
 
 /**
- * Returns a list of ratings for a particular post - sorted.
- *
- * @param stdClass $context
- * @param int $postid
- * @param string $sort
- * @return array Array of ratings or false
  * @deprecated since Moodle 2.0 MDL-21657 - please do not use this function any more.
  */
-function forum_get_ratings($context, $postid, $sort = "u.firstname ASC") {
-    debugging('forum_get_ratings() is deprecated.', DEBUG_DEVELOPER);
-    $options = new stdClass;
-    $options->context = $context;
-    $options->component = 'mod_forum';
-    $options->ratingarea = 'post';
-    $options->itemid = $postid;
-    $options->sort = "ORDER BY $sort";
-
-    $rm = new rating_manager();
-    return $rm->get_all_ratings_for_item($options);
+function forum_get_ratings() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Generate and return the track or no track link for a forum.
- *
- * @global object
- * @global object
- * @global object
- * @param object $forum the forum. Fields used are $forum->id and $forum->forcesubscribe.
- * @param array $messages
- * @param bool $fakelink
- * @return string
  * @deprecated since Moodle 2.0 MDL-14632 - please do not use this function any more.
  */
-function forum_get_tracking_link($forum, $messages=array(), $fakelink=true) {
-    debugging('forum_get_tracking_link() is deprecated.', DEBUG_DEVELOPER);
-
-    global $CFG, $USER, $PAGE, $OUTPUT;
-
-    static $strnotrackforum, $strtrackforum;
-
-    if (isset($messages['trackforum'])) {
-         $strtrackforum = $messages['trackforum'];
-    }
-    if (isset($messages['notrackforum'])) {
-         $strnotrackforum = $messages['notrackforum'];
-    }
-    if (empty($strtrackforum)) {
-        $strtrackforum = get_string('trackforum', 'forum');
-    }
-    if (empty($strnotrackforum)) {
-        $strnotrackforum = get_string('notrackforum', 'forum');
-    }
-
-    if (forum_tp_is_tracked($forum)) {
-        $linktitle = $strnotrackforum;
-        $linktext = $strnotrackforum;
-    } else {
-        $linktitle = $strtrackforum;
-        $linktext = $strtrackforum;
-    }
-
-    $link = '';
-    if ($fakelink) {
-        $PAGE->requires->js('/mod/forum/forum.js');
-        $PAGE->requires->js_function_call('forum_produce_tracking_link', Array($forum->id, $linktext, $linktitle));
-        // use <noscript> to print button in case javascript is not enabled
-        $link .= '<noscript>';
-    }
-    $url = new moodle_url('/mod/forum/settracking.php', array(
-            'id' => $forum->id,
-            'sesskey' => sesskey(),
-        ));
-    $link .= $OUTPUT->single_button($url, $linktext, 'get', array('title'=>$linktitle));
-
-    if ($fakelink) {
-        $link .= '</noscript>';
-    }
-
-    return $link;
+function forum_get_tracking_link() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Returns the count of records for the provided user and discussion.
- *
- * @global object
- * @global object
- * @param int $userid
- * @param int $discussionid
- * @return int
  * @deprecated since Moodle 2.0 MDL-14113 - please do not use this function any more.
  */
-function forum_tp_count_discussion_unread_posts($userid, $discussionid) {
-    debugging('forum_tp_count_discussion_unread_posts() is deprecated.', DEBUG_DEVELOPER);
-    global $CFG, $DB;
-
-    $cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;
-
-    $sql = 'SELECT COUNT(p.id) '.
-           'FROM {forum_posts} p '.
-           'LEFT JOIN {forum_read} r ON r.postid = p.id AND r.userid = ? '.
-           'WHERE p.discussion = ? '.
-                'AND p.modified >= ? AND r.id is NULL';
-
-    return $DB->count_records_sql($sql, array($userid, $discussionid, $cutoffdate));
+function forum_tp_count_discussion_unread_posts() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Converts a forum to use the Roles System
- *
  * @deprecated since Moodle 2.0 MDL-23479 - please do not use this function any more.
  */
 function forum_convert_to_roles() {
-    debugging('forum_convert_to_roles() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Returns all records in the 'forum_read' table matching the passed keys, indexed
- * by userid.
- *
- * @global object
- * @param int $userid
- * @param int $postid
- * @param int $discussionid
- * @param int $forumid
- * @return array
  * @deprecated since Moodle 2.0 MDL-14113 - please do not use this function any more.
  */
-function forum_tp_get_read_records($userid=-1, $postid=-1, $discussionid=-1, $forumid=-1) {
-    debugging('forum_tp_get_read_records() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    global $DB;
-    $select = '';
-    $params = array();
-
-    if ($userid > -1) {
-        if ($select != '') $select .= ' AND ';
-        $select .= 'userid = ?';
-        $params[] = $userid;
-    }
-    if ($postid > -1) {
-        if ($select != '') $select .= ' AND ';
-        $select .= 'postid = ?';
-        $params[] = $postid;
-    }
-    if ($discussionid > -1) {
-        if ($select != '') $select .= ' AND ';
-        $select .= 'discussionid = ?';
-        $params[] = $discussionid;
-    }
-    if ($forumid > -1) {
-        if ($select != '') $select .= ' AND ';
-        $select .= 'forumid = ?';
-        $params[] = $forumid;
-    }
-
-    return $DB->get_records_select('forum_read', $select, $params);
+function forum_tp_get_read_records() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Returns all read records for the provided user and discussion, indexed by postid.
- *
- * @global object
- * @param inti $userid
- * @param int $discussionid
  * @deprecated since Moodle 2.0 MDL-14113 - please do not use this function any more.
  */
-function forum_tp_get_discussion_read_records($userid, $discussionid) {
-    debugging('forum_tp_get_discussion_read_records() is deprecated and will not be replaced.', DEBUG_DEVELOPER);
-
-    global $DB;
-    $select = 'userid = ? AND discussionid = ?';
-    $fields = 'postid, firstread, lastread';
-    return $DB->get_records_select('forum_read', $select, array($userid, $discussionid), '', $fields);
+function forum_tp_get_discussion_read_records() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 // Deprecated in 2.3.
 
 /**
- * This function gets run whenever user is enrolled into course
- *
  * @deprecated since Moodle 2.3 MDL-33166 - please do not use this function any more.
- * @param stdClass $cp
- * @return void
  */
-function forum_user_enrolled($cp) {
-    debugging('forum_user_enrolled() is deprecated. Please use forum_user_role_assigned instead.', DEBUG_DEVELOPER);
-    global $DB;
-
-    // NOTE: this has to be as fast as possible - we do not want to slow down enrolments!
-    //       Originally there used to be 'mod/forum:initialsubscriptions' which was
-    //       introduced because we did not have enrolment information in earlier versions...
-
-    $sql = "SELECT f.id
-              FROM {forum} f
-         LEFT JOIN {forum_subscriptions} fs ON (fs.forum = f.id AND fs.userid = :userid)
-             WHERE f.course = :courseid AND f.forcesubscribe = :initial AND fs.id IS NULL";
-    $params = array('courseid'=>$cp->courseid, 'userid'=>$cp->userid, 'initial'=>FORUM_INITIALSUBSCRIBE);
-
-    $forums = $DB->get_records_sql($sql, $params);
-    foreach ($forums as $forum) {
-        \mod_forum\subscriptions::subscribe_user($cp->userid, $forum);
-    }
+function forum_user_enrolled() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
 // Deprecated in 2.4.
 
 /**
- * Checks to see if a user can view a particular post.
- *
  * @deprecated since Moodle 2.4 use forum_user_can_see_post() instead
- *
- * @param object $post
- * @param object $course
- * @param object $cm
- * @param object $forum
- * @param object $discussion
- * @param object $user
- * @return boolean
  */
-function forum_user_can_view_post($post, $course, $cm, $forum, $discussion, $user=null){
-    debugging('forum_user_can_view_post() is deprecated. Please use forum_user_can_see_post() instead.', DEBUG_DEVELOPER);
-    return forum_user_can_see_post($forum, $discussion, $post, $user, $cm);
+function forum_user_can_view_post() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 
@@ -509,204 +170,93 @@ define('FORUM_TRACKING_ON', 2);
  * @see shorten_text()
  */
 function forum_shorten_post($message) {
-    throw new coding_exception('forum_shorten_post() can not be used any more. Please use shorten_text($message, $CFG->forum_shortpost) instead.');
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. '
+        . 'Please use shorten_text($message, $CFG->forum_shortpost) instead.');
 }
 
 // Deprecated in 2.8.
 
 /**
- * @global object
- * @param int $userid
- * @param object $forum
- * @return bool
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::is_subscribed() instead
  */
-function forum_is_subscribed($userid, $forum) {
-    global $DB;
-    debugging("forum_is_subscribed() has been deprecated, please use \\mod_forum\\subscriptions::is_subscribed() instead.",
-            DEBUG_DEVELOPER);
-
-    // Note: The new function does not take an integer form of forum.
-    if (is_numeric($forum)) {
-        $forum = $DB->get_record('forum', array('id' => $forum));
-    }
-
-    return mod_forum\subscriptions::is_subscribed($userid, $forum);
+function forum_is_subscribed() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more.');
 }
 
 /**
- * Adds user to the subscriber list
- *
- * @param int $userid
- * @param int $forumid
- * @param context_module|null $context Module context, may be omitted if not known or if called for the current module set in page.
- * @param boolean $userrequest Whether the user requested this change themselves. This has an effect on whether
- * discussion subscriptions are removed too.
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::subscribe_user() instead
  */
-function forum_subscribe($userid, $forumid, $context = null, $userrequest = false) {
-    global $DB;
-    debugging("forum_subscribe() has been deprecated, please use \\mod_forum\\subscriptions::subscribe_user() instead.",
-            DEBUG_DEVELOPER);
-
-    // Note: The new function does not take an integer form of forum.
-    $forum = $DB->get_record('forum', array('id' => $forumid));
-    \mod_forum\subscriptions::subscribe_user($userid, $forum, $context, $userrequest);
+function forum_subscribe() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::subscribe_user() instead');
 }
 
 /**
- * Removes user from the subscriber list
- *
- * @param int $userid
- * @param int $forumid
- * @param context_module|null $context Module context, may be omitted if not known or if called for the current module set in page.
- * @param boolean $userrequest Whether the user requested this change themselves. This has an effect on whether
- * discussion subscriptions are removed too.
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::unsubscribe_user() instead
  */
-function forum_unsubscribe($userid, $forumid, $context = null, $userrequest = false) {
-    global $DB;
-    debugging("forum_unsubscribe() has been deprecated, please use \\mod_forum\\subscriptions::unsubscribe_user() instead.",
-            DEBUG_DEVELOPER);
-
-    // Note: The new function does not take an integer form of forum.
-    $forum = $DB->get_record('forum', array('id' => $forumid));
-    \mod_forum\subscriptions::unsubscribe_user($userid, $forum, $context, $userrequest);
+function forum_unsubscribe() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::unsubscribe_user() instead');
 }
 
 /**
- * Returns list of user objects that are subscribed to this forum.
- *
- * @param stdClass $course the course
- * @param stdClass $forum the forum
- * @param int $groupid group id, or 0 for all.
- * @param context_module $context the forum context, to save re-fetching it where possible.
- * @param string $fields requested user fields (with "u." table prefix)
- * @param boolean $considerdiscussions Whether to take discussion subscriptions and unsubscriptions into consideration.
- * @return array list of users.
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::fetch_subscribed_users() instead
   */
-function forum_subscribed_users($course, $forum, $groupid = 0, $context = null, $fields = null) {
-    debugging("forum_subscribed_users() has been deprecated, please use \\mod_forum\\subscriptions::fetch_subscribed_users() instead.",
-            DEBUG_DEVELOPER);
-
-    \mod_forum\subscriptions::fetch_subscribed_users($forum, $groupid, $context, $fields);
+function forum_subscribed_users() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::fetch_subscribed_users() instead');
 }
 
 /**
  * Determine whether the forum is force subscribed.
  *
- * @param object $forum
- * @return bool
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::is_forcesubscribed() instead
  */
 function forum_is_forcesubscribed($forum) {
-    debugging("forum_is_forcesubscribed() has been deprecated, please use \\mod_forum\\subscriptions::is_forcesubscribed() instead.",
-            DEBUG_DEVELOPER);
-
-    global $DB;
-    if (!isset($forum->forcesubscribe)) {
-       $forum = $DB->get_field('forum', 'forcesubscribe', array('id' => $forum));
-    }
-
-    return \mod_forum\subscriptions::is_forcesubscribed($forum);
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::is_forcesubscribed() instead');
 }
 
 /**
- * Set the subscription mode for a forum.
- *
- * @param int $forumid
- * @param mixed $value
- * @return bool
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::set_subscription_mode() instead
  */
 function forum_forcesubscribe($forumid, $value = 1) {
-    debugging("forum_forcesubscribe() has been deprecated, please use \\mod_forum\\subscriptions::set_subscription_mode() instead.",
-            DEBUG_DEVELOPER);
-
-    return \mod_forum\subscriptions::set_subscription_mode($forumid, $value);
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::set_subscription_mode() instead');
 }
 
 /**
- * Get the current subscription mode for the forum.
- *
- * @param int|stdClass $forumid
- * @param mixed $value
- * @return bool
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::get_subscription_mode() instead
  */
 function forum_get_forcesubscribed($forum) {
-    debugging("forum_get_forcesubscribed() has been deprecated, please use \\mod_forum\\subscriptions::get_subscription_mode() instead.",
-            DEBUG_DEVELOPER);
-
-    global $DB;
-    if (!isset($forum->forcesubscribe)) {
-       $forum = $DB->get_field('forum', 'forcesubscribe', array('id' => $forum));
-    }
-
-    return \mod_forum\subscriptions::get_subscription_mode($forumid, $value);
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::set_subscription_mode() instead');
 }
 
 /**
- * Get a list of forums in the specified course in which a user can change
- * their subscription preferences.
- *
- * @param stdClass $course The course from which to find subscribable forums.
- * @return array
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::is_subscribed in combination wtih
  * \mod_forum\subscriptions::fill_subscription_cache_for_course instead.
  */
-function forum_get_subscribed_forums($course) {
-    debugging("forum_get_subscribed_forums() has been deprecated, please see " .
-              "\\mod_forum\\subscriptions::is_subscribed::() " .
-              " and \\mod_forum\\subscriptions::fill_subscription_cache_for_course instead.",
-              DEBUG_DEVELOPER);
-
-    global $USER, $CFG, $DB;
-    $sql = "SELECT f.id
-              FROM {forum} f
-                   LEFT JOIN {forum_subscriptions} fs ON (fs.forum = f.id AND fs.userid = ?)
-             WHERE f.course = ?
-                   AND f.forcesubscribe <> ".FORUM_DISALLOWSUBSCRIBE."
-                   AND (f.forcesubscribe = ".FORUM_FORCESUBSCRIBE." OR fs.id IS NOT NULL)";
-    if ($subscribed = $DB->get_records_sql($sql, array($USER->id, $course->id))) {
-        foreach ($subscribed as $s) {
-            $subscribed[$s->id] = $s->id;
-        }
-        return $subscribed;
-    } else {
-        return array();
-    }
+function forum_get_subscribed_forums() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::is_subscribed(), and '
+        . \mod_forum\subscriptions::class . '::fill_subscription_cache_for_course() instead');
 }
 
 /**
- * Returns an array of forums that the current user is subscribed to and is allowed to unsubscribe from
- *
- * @return array An array of unsubscribable forums
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::get_unsubscribable_forums() instead
  */
 function forum_get_optional_subscribed_forums() {
-    debugging("forum_get_optional_subscribed_forums() has been deprecated, please use \\mod_forum\\subscriptions::get_unsubscribable_forums() instead.",
-            DEBUG_DEVELOPER);
-
-    return \mod_forum\subscriptions::get_unsubscribable_forums();
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::get_unsubscribable_forums() instead');
 }
 
 /**
- * Get the list of potential subscribers to a forum.
- *
- * @param object $forumcontext the forum context.
- * @param integer $groupid the id of a group, or 0 for all groups.
- * @param string $fields the list of fields to return for each user. As for get_users_by_capability.
- * @param string $sort sort order. As for get_users_by_capability.
- * @return array list of users.
  * @deprecated since Moodle 2.8 use \mod_forum\subscriptions::get_potential_subscribers() instead
  */
-function forum_get_potential_subscribers($forumcontext, $groupid, $fields, $sort = '') {
-    debugging("forum_get_potential_subscribers() has been deprecated, please use \\mod_forum\\subscriptions::get_potential_subscribers() instead.",
-            DEBUG_DEVELOPER);
-
-    \mod_forum\subscriptions::get_potential_subscribers($forumcontext, $groupid, $fields, $sort);
+function forum_get_potential_subscribers() {
+    throw new coding_exception(__FUNCTION__ . '() can not be used any more. Please use '
+        . \mod_forum\subscriptions::class . '::get_potential_subscribers() instead');
 }
 
 /**
diff --git a/mod/forum/tests/subscriptions_test.php b/mod/forum/tests/subscriptions_test.php
index 8b2d40bdd54..cdd98acefc3 100644
--- a/mod/forum/tests/subscriptions_test.php
+++ b/mod/forum/tests/subscriptions_test.php
@@ -220,11 +220,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently not subscribed to the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Check that the user is unsubscribed from the discussion too.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -262,36 +257,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
             'discussion'    => $discussion->id,
         )));
 
-        // The same thing should happen calling the deprecated versions of
-        // these functions.
-        // Subscribing to the forum should create a record in the subscriptions table, but not the forum discussion
-        // subscriptions table.
-        forum_subscribe($author->id, $forum->id);
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-        $this->assertEquals(1, $DB->count_records('forum_subscriptions', array(
-            'userid'        => $author->id,
-            'forum'         => $forum->id,
-        )));
-        $this->assertEquals(0, $DB->count_records('forum_discussion_subs', array(
-            'userid'        => $author->id,
-            'discussion'    => $discussion->id,
-        )));
-
-        // Unsubscribing should remove the record from the forum subscriptions table, and not modify the forum
-        // discussion subscriptions table.
-        forum_unsubscribe($author->id, $forum->id);
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-        $this->assertEquals(0, $DB->count_records('forum_subscriptions', array(
-            'userid'        => $author->id,
-            'forum'         => $forum->id,
-        )));
-        $this->assertEquals(0, $DB->count_records('forum_discussion_subs', array(
-            'userid'        => $author->id,
-            'discussion'    => $discussion->id,
-        )));
-
         // Enroling the user in the discussion should add one record to the forum discussion table without modifying the
         // form subscriptions.
         \mod_forum\subscriptions::subscribe_user_to_discussion($author->id, $discussion);
@@ -439,11 +404,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently not subscribed to the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
 
@@ -476,11 +436,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
 
@@ -506,11 +461,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently not subscribed to the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
 
@@ -523,11 +473,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still unsubscribed from the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // But subscribed to the discussion.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
     }
@@ -553,11 +498,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
 
@@ -567,11 +507,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // But unsubscribed from the discussion.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
     }
@@ -599,11 +534,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
 
@@ -629,11 +559,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // An attempt to unsubscribe again should result in a falsey return to indicate that no change was made.
         $this->assertFalse(\mod_forum\subscriptions::unsubscribe_user_from_discussion($author->id, $discussion));
 
@@ -668,16 +593,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // And is subscribed to the discussion again.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -699,11 +614,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // But unsubscribed from the discussion.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -747,11 +657,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still subscribed to the forum.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // But unsubscribed from the discussion.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -806,11 +711,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is currently unsubscribed to the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // Post a discussion to the forum.
         list($discussion, $post) = $this->helper_post_to_forum($forum, $author);
 
@@ -826,11 +726,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still unsubscribed from the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // But subscribed to the discussion.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -846,11 +741,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still unsubscribed from the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // And is unsubscribed from the discussion again.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -866,11 +756,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still unsubscribed from the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // And is subscribed to the discussion again.
         $this->assertTrue(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -886,11 +771,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         // Check that the user is still unsubscribed from the forum.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum));
 
-        // Check the deprecated function too.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
         // But unsubscribed from the discussion.
         $this->assertFalse(\mod_forum\subscriptions::is_subscribed($author->id, $forum, $discussion->id));
 
@@ -901,46 +781,6 @@ class mod_forum_subscriptions_testcase extends advanced_testcase {
         )));
     }
 
-    /**
-     * Test that the deprecated forum_is_subscribed accepts numeric forum IDs.
-     */
-    public function test_forum_is_subscribed_numeric() {
-        global $DB;
-
-        $this->resetAfterTest(true);
-
-        // Create a course, with a forum.
-        $course = $this->getDataGenerator()->create_course();
-
-        $options = array('course' => $course->id, 'forcesubscribe' => FORUM_CHOOSESUBSCRIBE);
-        $forum = $this->getDataGenerator()->create_module('forum', $options);
-
-        // Create a user enrolled in the course as a students.
-        list($author) = $this->helper_create_users($course, 1);
-
-        // Check that the user is currently unsubscribed to the forum.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum->id));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
-        // It should match the result of when it's called with the forum object.
-        $this->assertFalse(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
-        // And when the user is subscribed, we should also get the correct result.
-        \mod_forum\subscriptions::subscribe_user($author->id, $forum);
-
-        $this->assertTrue(forum_is_subscribed($author->id, $forum->id));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-
-        // It should match the result of when it's called with the forum object.
-        $this->assertTrue(forum_is_subscribed($author->id, $forum));
-        $this->assertEquals(1, count($this->getDebuggingMessages()));
-        $this->resetDebugging();
-    }
-
     /**
      * Test that the correct users are returned when fetching subscribed users from a forum where users can choose to
      * subscribe and unsubscribe.
diff --git a/mod/forum/upgrade.txt b/mod/forum/upgrade.txt
index 572ffe52a4a..bbbe97a9b35 100644
--- a/mod/forum/upgrade.txt
+++ b/mod/forum/upgrade.txt
@@ -1,6 +1,36 @@
 This files describes API changes in /mod/forum/*,
 information provided here is intended especially for developers.
 
+=== 3.2 ===
+ * The following functions have been finally deprecated and should no longer be used.
+  - forum_count_unrated_posts
+  - forum_tp_count_discussion_read_records
+  - forum_get_user_discussions
+  - forum_tp_count_forum_posts
+  - forum_tp_count_forum_read_records
+  - forum_get_open_modes
+  - forum_get_child_posts
+  - forum_get_discussion_posts
+  - forum_get_ratings
+  - forum_get_tracking_link
+  - forum_tp_count_discussion_unread_posts
+  - forum_convert_to_roles
+  - forum_tp_get_read_records
+  - forum_tp_get_discussion_read_records
+  - forum_user_enrolled
+  - forum_user_can_view_post
+  - forum_shorten_post
+  - forum_is_subscribed
+  - forum_subscribe
+  - forum_unsubscribe
+  - forum_subscribed_users
+  - forum_is_forcesubscribed
+  - forum_forcesubscribe
+  - forum_get_forcesubscribed
+  - forum_get_subscribed_forums
+  - forum_get_optional_subscribed_forums
+  - forum_get_potential_subscribers
+
 === 3.1 ===
  * The inteface to forum_get_email_message_id() has changed and no longer needs the $host argument.