diff --git a/admin/tool/log/store/legacy/classes/log/store.php b/admin/tool/log/store/legacy/classes/log/store.php
index bcb1d546649..aa4a6855226 100644
--- a/admin/tool/log/store/legacy/classes/log/store.php
+++ b/admin/tool/log/store/legacy/classes/log/store.php
@@ -17,7 +17,7 @@
 /**
  * Legacy log reader.
  * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
- * @todo  MDL-52805 This is to be removed in Moodle 4.0
+ * @todo  MDL-52805 This is to be removed in Moodle 3.10
  *
  * @package    logstore_legacy
  * @copyright  2013 Petr Skoda {@link http://skodak.org}
@@ -34,7 +34,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
 
     /**
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo  MDL-52805 This is to be removed in Moodle 4.0
+     * @todo  MDL-52805 This is to be removed in Moodle 3.10
      *
      * @param \tool_log\log\manager $manager
      */
@@ -93,7 +93,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
 
     /**
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo MDL-52805 This will be removed in Moodle 4.0
+     * @todo MDL-52805 This will be removed in Moodle 3.10
      *
      * @param  string $selectwhere
      * @param  array  $params
@@ -134,7 +134,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
     /**
      * Fetch records using given criteria returning a Traversable object.
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo MDL-52805 This will be removed in Moodle 4.0
+     * @todo MDL-52805 This will be removed in Moodle 3.10
      *
      * Note that the traversable object contains a moodle_recordset, so
      * remember that is important that you call close() once you finish
@@ -168,7 +168,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
     /**
      * Returns an event from the log data.
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo MDL-52805 This will be removed in Moodle 4.0
+     * @todo MDL-52805 This will be removed in Moodle 3.10
      *
      * @param stdClass $data Log data
      * @return \core\event\base
@@ -179,7 +179,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
 
     /**
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo MDL-52805 This will be removed in Moodle 4.0
+     * @todo MDL-52805 This will be removed in Moodle 3.10
      *
      * @param  string $selectwhere
      * @param  array  $params
@@ -202,7 +202,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
     /**
      * Are the new events appearing in the reader?
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo MDL-52805 This will be removed in Moodle 4.0
+     * @todo MDL-52805 This will be removed in Moodle 3.10
      *
      * @return bool true means new log events are being added, false means no new data will be added
      */
@@ -212,7 +212,7 @@ class store implements \tool_log\log\store, \core\log\sql_reader {
 
     /**
      * @deprecated since Moodle 3.6 MDL-52953 - Please use supported log stores such as "standard" or "external" instead.
-     * @todo MDL-52805 This will be removed in Moodle 4.0
+     * @todo MDL-52805 This will be removed in Moodle 3.10
      */
     public function dispose() {
     }
diff --git a/calendar/classes/external/calendar_event_exporter.php b/calendar/classes/external/calendar_event_exporter.php
index 7d548f918a4..e943e9c9a37 100644
--- a/calendar/classes/external/calendar_event_exporter.php
+++ b/calendar/classes/external/calendar_event_exporter.php
@@ -369,7 +369,7 @@ class calendar_event_exporter extends event_exporter_base {
      * and the module's minimum timestamp limit.
      *
      * @deprecated since Moodle 3.6. Please use get_timestamp_min_limit().
-     * @todo final deprecation. To be removed in Moodle 4.0
+     * @todo final deprecation. To be removed in Moodle 3.10
      * @param DateTimeInterface $starttime The event start time
      * @param array $min The module's minimum limit for the event
      * @return array Returns an array with mindaytimestamp and mindayerror keys.
@@ -385,7 +385,7 @@ class calendar_event_exporter extends event_exporter_base {
      * and the module's maximum timestamp limit.
      *
      * @deprecated since Moodle 3.6. Please use get_timestamp_max_limit().
-     * @todo final deprecation. To be removed in Moodle 4.0
+     * @todo final deprecation. To be removed in Moodle 3.10
      * @param DateTimeInterface $starttime The event start time
      * @param array $max The module's maximum limit for the event
      * @return array Returns an array with maxdaytimestamp and maxdayerror keys.
diff --git a/lib/adminlib.php b/lib/adminlib.php
index b93d393d210..69fdd79d219 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -3276,7 +3276,7 @@ class admin_setting_configselect extends admin_setting {
      * an empty string '' if the value is OK, or an error message if not.
      *
      * @param callable|null $validatefunction Validate function or null to clear
-     * @since Moodle 4.0
+     * @since Moodle 3.10
      */
     public function set_validate_function(?callable $validatefunction = null) {
         $this->validatefunction = $validatefunction;
@@ -3362,7 +3362,7 @@ class admin_setting_configselect extends admin_setting {
      *
      * @param string $data New value being set
      * @return string Empty string if valid, or error message text
-     * @since Moodle 4.0
+     * @since Moodle 3.10
      */
     protected function validate_setting(string $data): string {
         // If validation function is specified, call it now.
diff --git a/lib/classes/lock/db_record_lock_factory.php b/lib/classes/lock/db_record_lock_factory.php
index 4dfec49c4de..c703a2fc1a1 100644
--- a/lib/classes/lock/db_record_lock_factory.php
+++ b/lib/classes/lock/db_record_lock_factory.php
@@ -92,7 +92,7 @@ class db_record_lock_factory implements lock_factory {
     /**
      * Multiple locks for the same resource can be held by a single process.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @return boolean - False - not process specific.
      */
     public function supports_recursion() {
@@ -192,7 +192,7 @@ class db_record_lock_factory implements lock_factory {
     /**
      * Extend a lock that was previously obtained with @lock.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param lock $lock - a lock obtained from this factory.
      * @param int $maxlifetime - the new lifetime for the lock (in seconds).
      * @return boolean - true if the lock was extended.
diff --git a/lib/classes/lock/file_lock_factory.php b/lib/classes/lock/file_lock_factory.php
index b7716399007..87b93803571 100644
--- a/lib/classes/lock/file_lock_factory.php
+++ b/lib/classes/lock/file_lock_factory.php
@@ -109,7 +109,7 @@ class file_lock_factory implements lock_factory {
     /**
      * Multiple locks for the same resource cannot be held from a single process.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @return boolean - False
      */
     public function supports_recursion() {
@@ -193,7 +193,7 @@ class file_lock_factory implements lock_factory {
     /**
      * Extend a lock that was previously obtained with @lock.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param lock $lock - not used
      * @param int $maxlifetime - not used
      * @return boolean - true if the lock was extended.
diff --git a/lib/classes/lock/installation_lock_factory.php b/lib/classes/lock/installation_lock_factory.php
index 0874cedc610..628a815ee4c 100644
--- a/lib/classes/lock/installation_lock_factory.php
+++ b/lib/classes/lock/installation_lock_factory.php
@@ -76,7 +76,7 @@ class installation_lock_factory implements lock_factory {
     /**
      * Multiple locks for the same resource cannot be held from a single process.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @return boolean - False
      */
     public function supports_recursion() {
@@ -118,7 +118,7 @@ class installation_lock_factory implements lock_factory {
     /**
      * Extend a lock that was previously obtained with @lock.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param lock $lock - not used
      * @param int $maxlifetime - not used
      * @return boolean - true if the lock was extended.
diff --git a/lib/classes/lock/lock.php b/lib/classes/lock/lock.php
index f67083c83b4..7012bcf1888 100644
--- a/lib/classes/lock/lock.php
+++ b/lib/classes/lock/lock.php
@@ -81,7 +81,7 @@ class lock {
     /**
      * Extend the lifetime of this lock. Not supported by all factories.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param int $maxlifetime - the new lifetime for the lock (in seconds).
      * @return bool
      */
diff --git a/lib/classes/lock/lock_factory.php b/lib/classes/lock/lock_factory.php
index c0d32b0a1ff..9ca9782c33e 100644
--- a/lib/classes/lock/lock_factory.php
+++ b/lib/classes/lock/lock_factory.php
@@ -63,7 +63,7 @@ interface lock_factory {
     /**
      * Supports recursion.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @return boolean - True if attempting to get 2 locks on the same resource will "stack"
      */
     public function supports_recursion();
@@ -99,7 +99,7 @@ interface lock_factory {
     /**
      * Extend the timeout on a held lock.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param lock $lock - lock obtained from this factory
      * @param int $maxlifetime - new max time to hold the lock
      * @return boolean - True if the lock was extended.
diff --git a/lib/classes/lock/mysql_lock_factory.php b/lib/classes/lock/mysql_lock_factory.php
index 753741b4655..29e3abcfadc 100644
--- a/lib/classes/lock/mysql_lock_factory.php
+++ b/lib/classes/lock/mysql_lock_factory.php
@@ -106,7 +106,7 @@ class mysql_lock_factory implements lock_factory {
      * Hard coded to false and workaround inconsistent support in different
      * versions of MySQL / MariaDB.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @return boolean - false
      */
     public function supports_recursion() {
@@ -169,7 +169,7 @@ class mysql_lock_factory implements lock_factory {
     /**
      * Extend a lock that was previously obtained with @lock.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param lock $lock - a lock obtained from this factory.
      * @param int $maxlifetime - the new lifetime for the lock (in seconds).
      * @return boolean - true if the lock was extended.
diff --git a/lib/classes/lock/postgres_lock_factory.php b/lib/classes/lock/postgres_lock_factory.php
index 1d18967d59c..a4deb15cf44 100644
--- a/lib/classes/lock/postgres_lock_factory.php
+++ b/lib/classes/lock/postgres_lock_factory.php
@@ -120,7 +120,7 @@ class postgres_lock_factory implements lock_factory {
     /**
      * Multiple locks for the same resource can NOT be held by a single process.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @return boolean - false.
      */
     public function supports_recursion() {
@@ -206,7 +206,7 @@ class postgres_lock_factory implements lock_factory {
     /**
      * Extend a lock that was previously obtained with @lock.
      *
-     * @deprecated since Moodle 4.0.
+     * @deprecated since Moodle 3.10.
      * @param lock $lock - a lock obtained from this factory.
      * @param int $maxlifetime - the new lifetime for the lock (in seconds).
      * @return boolean - true if the lock was extended.
diff --git a/lib/deprecatedlib.php b/lib/deprecatedlib.php
index 48661cb6bf8..3420ebbaaca 100644
--- a/lib/deprecatedlib.php
+++ b/lib/deprecatedlib.php
@@ -3357,7 +3357,7 @@ function user_get_participants($courseid, $groupid = 0, $accesssince, $roleid, $
  *
  * Calls {@see core_course_category::make_categories_list()} to build the list.
  *
- * @deprecated since Moodle 4.0
+ * @deprecated since Moodle 3.10
  * @todo This will be finally removed for Moodle 4.4 as part of MDL-69124.
  * @return array array mapping course category id to the display name
  */
diff --git a/search/classes/manager.php b/search/classes/manager.php
index 8a768622ed6..15041c793c7 100644
--- a/search/classes/manager.php
+++ b/search/classes/manager.php
@@ -1196,7 +1196,7 @@ class manager {
             } else if (count($result) === 5) {
                 // Backward compatibility for engines that don't return a batch count.
                 [$numrecords, $numdocs, $numdocsignored, $lastindexeddoc, $partial] = $result;
-                // Deprecated since Moodle 4.0 MDL-68690.
+                // Deprecated since Moodle 3.10 MDL-68690.
                 // TODO: MDL-68776 This will be deleted in Moodle 4.4.
                 debugging('engine::add_documents() should return $batches (5-value return is deprecated)',
                         DEBUG_DEVELOPER);
@@ -1361,7 +1361,7 @@ class manager {
             } else if (count($result) === 5) {
                 // Backward compatibility for engines that don't return a batch count.
                 [$numrecords, $numdocs, $numdocsignored, $lastindexeddoc, $partial] = $result;
-                // Deprecated since Moodle 4.0 MDL-68690.
+                // Deprecated since Moodle 3.10 MDL-68690.
                 // TODO: MDL-68776 This will be deleted in Moodle 4.4 (as should the below bit).
                 debugging('engine::add_documents() should return $batches (5-value return is deprecated)',
                         DEBUG_DEVELOPER);