diff --git a/admin/tool/dataprivacy/classes/external.php b/admin/tool/dataprivacy/classes/external.php
index 4c4e71944ab..7306eb20d9d 100644
--- a/admin/tool/dataprivacy/classes/external.php
+++ b/admin/tool/dataprivacy/classes/external.php
@@ -1613,7 +1613,7 @@ class external extends external_api {
      */
     private static function get_tree_node_structure($allowchildbranches = true) {
         $fields = [
-            'text' => new external_value(PARAM_TEXT, 'The node text', VALUE_REQUIRED),
+            'text' => new external_value(PARAM_RAW, 'The node text', VALUE_REQUIRED),
             'expandcontextid' => new external_value(PARAM_INT, 'The contextid this node expands', VALUE_REQUIRED),
             'expandelement' => new external_value(PARAM_ALPHA, 'What element is this node expanded to', VALUE_REQUIRED),
             'contextid' => new external_value(PARAM_INT, 'The node contextid', VALUE_REQUIRED),
diff --git a/admin/tool/mobile/classes/external.php b/admin/tool/mobile/classes/external.php
index b3c56bb3e01..8b9057c0f04 100644
--- a/admin/tool/mobile/classes/external.php
+++ b/admin/tool/mobile/classes/external.php
@@ -139,7 +139,7 @@ class external extends external_api {
             array(
                 'wwwroot' => new external_value(PARAM_RAW, 'Site URL.'),
                 'httpswwwroot' => new external_value(PARAM_RAW, 'Site https URL (if httpslogin is enabled).'),
-                'sitename' => new external_value(PARAM_TEXT, 'Site name.'),
+                'sitename' => new external_value(PARAM_RAW, 'Site name.'),
                 'guestlogin' => new external_value(PARAM_INT, 'Whether guest login is enabled.'),
                 'rememberusername' => new external_value(PARAM_INT, 'Values: 0 for No, 1 for Yes, 2 for optional.'),
                 'authloginviaemail' => new external_value(PARAM_INT, 'Whether log in via email is enabled.'),
diff --git a/auth/email/classes/external.php b/auth/email/classes/external.php
index 782f0336c4e..52e7227bae7 100644
--- a/auth/email/classes/external.php
+++ b/auth/email/classes/external.php
@@ -147,12 +147,12 @@ class auth_email_external extends external_api {
                         array(
                             'id' => new external_value(PARAM_INT, 'Profile field id', VALUE_OPTIONAL),
                             'shortname' => new external_value(PARAM_ALPHANUMEXT, 'Profile field shortname', VALUE_OPTIONAL),
-                            'name' => new external_value(PARAM_TEXT, 'Profield field name', VALUE_OPTIONAL),
+                            'name' => new external_value(PARAM_RAW, 'Profield field name', VALUE_OPTIONAL),
                             'datatype' => new external_value(PARAM_ALPHANUMEXT, 'Profield field datatype', VALUE_OPTIONAL),
                             'description' => new external_value(PARAM_RAW, 'Profield field description', VALUE_OPTIONAL),
                             'descriptionformat' => new external_format_value('description'),
                             'categoryid' => new external_value(PARAM_INT, 'Profield field category id', VALUE_OPTIONAL),
-                            'categoryname' => new external_value(PARAM_TEXT, 'Profield field category name', VALUE_OPTIONAL),
+                            'categoryname' => new external_value(PARAM_RAW, 'Profield field category name', VALUE_OPTIONAL),
                             'sortorder' => new external_value(PARAM_INT, 'Profield field sort order', VALUE_OPTIONAL),
                             'required' => new external_value(PARAM_INT, 'Profield field required', VALUE_OPTIONAL),
                             'locked' => new external_value(PARAM_INT, 'Profield field locked', VALUE_OPTIONAL),
diff --git a/auth/email/tests/external_test.php b/auth/email/tests/external_test.php
index 0220640e9da..f62f95c1102 100644
--- a/auth/email/tests/external_test.php
+++ b/auth/email/tests/external_test.php
@@ -93,6 +93,51 @@ class auth_email_external_testcase extends externallib_advanced_testcase {
         $this->assertEquals('textarea', $namedarray['sometext']['datatype']);
     }
 
+    /**
+     * Test get_signup_settings with mathjax in a profile field.
+     */
+    public function test_get_signup_settings_with_mathjax_in_profile_fields() {
+        global $CFG, $DB;
+
+        require_once($CFG->dirroot . '/lib/externallib.php');
+
+        // Enable MathJax filter in content and headings.
+        $this->configure_filters([
+            ['name' => 'mathjaxloader', 'state' => TEXTFILTER_ON, 'move' => -1, 'applytostrings' => true],
+        ]);
+
+        // Create category with MathJax and a new field with MathJax.
+        $categoryname = 'Cat $$(a+b)=2$$';
+        $fieldname = 'Some text $$(a+b)=2$$';
+        $categoryid = $DB->insert_record('user_info_category', array('name' => $categoryname, 'sortorder' => 1));
+        $field3 = $DB->insert_record('user_info_field', array(
+                'shortname' => 'mathjaxname', 'name' => $fieldname, 'categoryid' => $categoryid,
+                'datatype' => 'textarea', 'signup' => 1, 'visible' => 1, 'required' => 1, 'sortorder' => 2));
+
+        $result = auth_email_external::get_signup_settings();
+        $result = external_api::clean_returnvalue(auth_email_external::get_signup_settings_returns(), $result);
+
+        // Format the original data.
+        $sitecontext = context_system::instance();
+        $categoryname = external_format_string($categoryname, $sitecontext->id);
+        $fieldname = external_format_string($fieldname, $sitecontext->id);
+
+        // Whip up a array with named entries to easily check against.
+        $namedarray = array();
+        foreach ($result['profilefields'] as $key => $value) {
+            $namedarray[$value['shortname']] = $value;
+        }
+
+        // Check the new profile field.
+        $this->assertArrayHasKey('mathjaxname', $namedarray);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">',
+                $namedarray['mathjaxname']['categoryname']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">',
+                $namedarray['mathjaxname']['name']);
+        $this->assertEquals($categoryname, $namedarray['mathjaxname']['categoryname']);
+        $this->assertEquals($fieldname, $namedarray['mathjaxname']['name']);
+    }
+
     public function test_signup_user() {
         global $DB;
 
diff --git a/blocks/classes/external.php b/blocks/classes/external.php
index e9f09ac3837..cc0818097b6 100644
--- a/blocks/classes/external.php
+++ b/blocks/classes/external.php
@@ -59,7 +59,7 @@ class core_block_external extends external_api {
                 'visible'       => new external_value(PARAM_BOOL, 'Whether the block is visible.', VALUE_OPTIONAL),
                 'contents'      => new external_single_structure(
                     array(
-                        'title'         => new external_value(PARAM_TEXT, 'Block title.'),
+                        'title'         => new external_value(PARAM_RAW, 'Block title.'),
                         'content'       => new external_value(PARAM_RAW, 'Block contents.'),
                         'contentformat' => new external_format_value('content'),
                         'footer'        => new external_value(PARAM_RAW, 'Block footer.'),
diff --git a/blocks/tests/externallib_test.php b/blocks/tests/externallib_test.php
index ee1b61b9db9..f5bb942308d 100644
--- a/blocks/tests/externallib_test.php
+++ b/blocks/tests/externallib_test.php
@@ -235,6 +235,85 @@ class core_block_externallib_testcase extends externallib_advanced_testcase {
         $this->assertEquals(5, $configcounts);
     }
 
+    /**
+     * Test get_course_blocks contents with mathjax.
+     */
+    public function test_get_course_blocks_contents_with_mathjax() {
+        global $DB, $CFG;
+
+        require_once($CFG->dirroot . '/lib/externallib.php');
+
+        $this->resetAfterTest(true);
+
+        // Enable MathJax filter in content and headings.
+        $this->configure_filters([
+            ['name' => 'mathjaxloader', 'state' => TEXTFILTER_ON, 'move' => -1, 'applytostrings' => true],
+        ]);
+
+        // Create a few stuff to test with.
+        $user = $this->getDataGenerator()->create_user();
+        $course = $this->getDataGenerator()->create_course();
+        $studentrole = $DB->get_record('role', array('shortname' => 'student'));
+        $this->getDataGenerator()->enrol_user($user->id, $course->id, $studentrole->id);
+        $coursecontext = context_course::instance($course->id);
+
+        // Create a HTML block.
+        $title = 'My block $$(a+b)=2$$';
+        $body = 'My block contents $$(a+b)=2$$';
+        $bodyformat = FORMAT_MOODLE;
+        $page = new moodle_page();
+        $page->set_context($coursecontext);
+        $page->set_pagelayout('course');
+        $course->format = course_get_format($course)->get_format();
+        $page->set_pagetype('course-view-' . $course->format);
+        $page->blocks->load_blocks();
+        $newblock = 'html';
+        $page->blocks->add_block_at_end_of_default_region($newblock);
+
+        $this->setUser($user);
+        // Re-create the page.
+        $page = new moodle_page();
+        $page->set_context($coursecontext);
+        $page->set_pagelayout('course');
+        $course->format = course_get_format($course)->get_format();
+        $page->set_pagetype('course-view-' . $course->format);
+        $page->blocks->load_blocks();
+        $blocks = $page->blocks->get_blocks_for_region($page->blocks->get_default_region());
+        $block = end($blocks);
+        $block = block_instance('html', $block->instance);
+        $nonscalar = [
+            'something' => true,
+        ];
+        $configdata = (object) [
+            'title' => $title,
+            'text' => [
+                'itemid' => 0,
+                'text' => $body,
+                'format' => $bodyformat,
+            ],
+            'nonscalar' => $nonscalar
+        ];
+        $block->instance_config_save((object) $configdata);
+
+        // Check for the new block.
+        $result = core_block_external::get_course_blocks($course->id, true);
+        $result = external_api::clean_returnvalue(core_block_external::get_course_blocks_returns(), $result);
+
+        // Format the original data.
+        $sitecontext = context_system::instance();
+        $title = external_format_string($title, $coursecontext->id);
+        list($body, $bodyformat) = external_format_text($body, $bodyformat, $coursecontext->id, 'block_html', 'content');
+
+        // Check that the block data is formatted.
+        $this->assertCount(1, $result['blocks']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">',
+                $result['blocks'][0]['contents']['title']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">',
+                $result['blocks'][0]['contents']['content']);
+        $this->assertEquals($title, $result['blocks'][0]['contents']['title']);
+        $this->assertEquals($body, $result['blocks'][0]['contents']['content']);
+    }
+
     /**
      * Test user get default dashboard blocks.
      */
diff --git a/calendar/externallib.php b/calendar/externallib.php
index 3f186f1ee86..b2c94b546b0 100644
--- a/calendar/externallib.php
+++ b/calendar/externallib.php
@@ -319,6 +319,7 @@ class core_calendar_external extends external_api {
             $event = (array) $eventobj;
             // Description formatting.
             $calendareventobj = new calendar_event($event);
+            $event['name'] = $calendareventobj->format_external_name();
             list($event['description'], $event['format']) = $calendareventobj->format_external_text();
 
             if ($hassystemcap) {
@@ -365,7 +366,7 @@ class core_calendar_external extends external_api {
                 'events' => new external_multiple_structure( new external_single_structure(
                         array(
                             'id' => new external_value(PARAM_INT, 'event id'),
-                            'name' => new external_value(PARAM_TEXT, 'event name'),
+                            'name' => new external_value(PARAM_RAW, 'event name'),
                             'description' => new external_value(PARAM_RAW, 'Description', VALUE_OPTIONAL, null, NULL_ALLOWED),
                             'format' => new external_format_value('description'),
                             'courseid' => new external_value(PARAM_INT, 'course id'),
@@ -745,7 +746,7 @@ class core_calendar_external extends external_api {
                         'events' => new external_multiple_structure( new external_single_structure(
                                 array(
                                     'id' => new external_value(PARAM_INT, 'event id'),
-                                    'name' => new external_value(PARAM_TEXT, 'event name'),
+                                    'name' => new external_value(PARAM_RAW, 'event name'),
                                     'description' => new external_value(PARAM_RAW, 'Description', VALUE_OPTIONAL),
                                     'format' => new external_format_value('description'),
                                     'courseid' => new external_value(PARAM_INT, 'course id'),
diff --git a/calendar/lib.php b/calendar/lib.php
index aba329f6db8..1fceea977d4 100644
--- a/calendar/lib.php
+++ b/calendar/lib.php
@@ -967,6 +967,22 @@ class calendar_event {
         }
     }
 
+    /**
+     * Format the event name using the external API.
+     *
+     * This function should we used when text formatting is required in external functions.
+     *
+     * @return string Formatted name.
+     */
+    public function format_external_name() {
+        if ($this->editorcontext === null) {
+            // Switch on the event type to decide upon the appropriate context to use for this event.
+            $this->editorcontext = $this->get_context();
+        }
+
+        return external_format_string($this->properties->name, $this->editorcontext->id);
+    }
+
     /**
      * Format the text using the external API.
      *
diff --git a/calendar/tests/externallib_test.php b/calendar/tests/externallib_test.php
index fc5ea7ec35c..1d41b310bcb 100644
--- a/calendar/tests/externallib_test.php
+++ b/calendar/tests/externallib_test.php
@@ -542,6 +542,42 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
         $this->assertEquals($category2->id, $events['events'][1]['categoryid']);
     }
 
+    /**
+     * Test get_calendar_events with mathjax in the name.
+     */
+    public function test_get_calendar_events_with_mathjax() {
+        global $USER;
+
+        $this->resetAfterTest(true);
+        set_config('calendar_adminseesall', 1);
+        $this->setAdminUser();
+
+        // Enable MathJax filter in content and headings.
+        $this->configure_filters([
+            ['name' => 'mathjaxloader', 'state' => TEXTFILTER_ON, 'move' => -1, 'applytostrings' => true],
+        ]);
+
+        // Create a site event with mathjax in the name and description.
+        $siteevent = $this->create_calendar_event('Site Event $$(a+b)=2$$', $USER->id, 'site', 0, time(),
+                ['description' => 'Site Event Description $$(a+b)=2$$']);
+
+        // Now call the WebService.
+        $events = core_calendar_external::get_calendar_events();
+        $events = external_api::clean_returnvalue(core_calendar_external::get_calendar_events_returns(), $events);
+
+        // Format the original data.
+        $sitecontext = context_system::instance();
+        $siteevent->name = $siteevent->format_external_name();
+        list($siteevent->description, $siteevent->descriptionformat) = $siteevent->format_external_text();
+
+        // Check that the event data is formatted.
+        $this->assertCount(1, $events['events']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $events['events'][0]['name']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $events['events'][0]['description']);
+        $this->assertEquals($siteevent->name, $events['events'][0]['name']);
+        $this->assertEquals($siteevent->description, $events['events'][0]['description']);
+    }
+
     /**
      * Test core_calendar_external::create_calendar_events
      */
diff --git a/course/externallib.php b/course/externallib.php
index 74fa9871cd6..a4140fb79c3 100644
--- a/course/externallib.php
+++ b/course/externallib.php
@@ -426,7 +426,7 @@ class core_course_external extends external_api {
             new external_single_structure(
                 array(
                     'id' => new external_value(PARAM_INT, 'Section ID'),
-                    'name' => new external_value(PARAM_TEXT, 'Section name'),
+                    'name' => new external_value(PARAM_RAW, 'Section name'),
                     'visible' => new external_value(PARAM_INT, 'is the section visible', VALUE_OPTIONAL),
                     'summary' => new external_value(PARAM_RAW, 'Section description'),
                     'summaryformat' => new external_format_value('summary'),
@@ -669,12 +669,12 @@ class core_course_external extends external_api {
                 new external_single_structure(
                         array(
                             'id' => new external_value(PARAM_INT, 'course id'),
-                            'shortname' => new external_value(PARAM_TEXT, 'course short name'),
+                            'shortname' => new external_value(PARAM_RAW, 'course short name'),
                             'categoryid' => new external_value(PARAM_INT, 'category id'),
                             'categorysortorder' => new external_value(PARAM_INT,
                                     'sort order into the category', VALUE_OPTIONAL),
-                            'fullname' => new external_value(PARAM_TEXT, 'full name'),
-                            'displayname' => new external_value(PARAM_TEXT, 'course display name'),
+                            'fullname' => new external_value(PARAM_RAW, 'full name'),
+                            'displayname' => new external_value(PARAM_RAW, 'course display name'),
                             'idnumber' => new external_value(PARAM_RAW, 'id number', VALUE_OPTIONAL),
                             'summary' => new external_value(PARAM_RAW, 'summary'),
                             'summaryformat' => new external_format_value('summary'),
@@ -729,7 +729,7 @@ class core_course_external extends external_api {
                              ),
                             'customfields' => new external_multiple_structure(
                                 new external_single_structure(
-                                    ['name' => new external_value(PARAM_TEXT, 'The name of the custom field'),
+                                    ['name' => new external_value(PARAM_RAW, 'The name of the custom field'),
                                      'shortname' => new external_value(PARAM_ALPHANUMEXT, 'The shortname of the custom field'),
                                      'type'  => new external_value(PARAM_COMPONENT,
                                          'The type of the custom field - text, checkbox...'),
@@ -939,7 +939,7 @@ class core_course_external extends external_api {
             new external_single_structure(
                 array(
                     'id'       => new external_value(PARAM_INT, 'course id'),
-                    'shortname' => new external_value(PARAM_TEXT, 'short name'),
+                    'shortname' => new external_value(PARAM_RAW, 'short name'),
                 )
             )
         );
@@ -1485,7 +1485,7 @@ class core_course_external extends external_api {
         return new external_single_structure(
             array(
                 'id'       => new external_value(PARAM_INT, 'course id'),
-                'shortname' => new external_value(PARAM_TEXT, 'short name'),
+                'shortname' => new external_value(PARAM_RAW, 'short name'),
             )
         );
     }
@@ -1963,7 +1963,7 @@ class core_course_external extends external_api {
             new external_single_structure(
                 array(
                     'id' => new external_value(PARAM_INT, 'category id'),
-                    'name' => new external_value(PARAM_TEXT, 'category name'),
+                    'name' => new external_value(PARAM_RAW, 'category name'),
                     'idnumber' => new external_value(PARAM_RAW, 'category id number', VALUE_OPTIONAL),
                     'description' => new external_value(PARAM_RAW, 'category description'),
                     'descriptionformat' => new external_format_value('description'),
@@ -2069,7 +2069,7 @@ class core_course_external extends external_api {
             new external_single_structure(
                 array(
                     'id' => new external_value(PARAM_INT, 'new category id'),
-                    'name' => new external_value(PARAM_TEXT, 'new category name'),
+                    'name' => new external_value(PARAM_RAW, 'new category name'),
                 )
             )
         );
@@ -2607,11 +2607,11 @@ class core_course_external extends external_api {
     protected static function get_course_structure($onlypublicdata = true) {
         $coursestructure = array(
             'id' => new external_value(PARAM_INT, 'course id'),
-            'fullname' => new external_value(PARAM_TEXT, 'course full name'),
-            'displayname' => new external_value(PARAM_TEXT, 'course display name'),
-            'shortname' => new external_value(PARAM_TEXT, 'course short name'),
+            'fullname' => new external_value(PARAM_RAW, 'course full name'),
+            'displayname' => new external_value(PARAM_RAW, 'course display name'),
+            'shortname' => new external_value(PARAM_RAW, 'course short name'),
             'categoryid' => new external_value(PARAM_INT, 'category id'),
-            'categoryname' => new external_value(PARAM_TEXT, 'category name'),
+            'categoryname' => new external_value(PARAM_RAW, 'category name'),
             'sortorder' => new external_value(PARAM_INT, 'Sort order in the category', VALUE_OPTIONAL),
             'summary' => new external_value(PARAM_RAW, 'summary'),
             'summaryformat' => new external_format_value('summary'),
@@ -2861,7 +2861,7 @@ class core_course_external extends external_api {
                             new external_single_structure(
                                 array(
                                     'id' => new external_value(PARAM_ALPHANUMEXT, 'Outcome id'),
-                                    'name'  => new external_value(PARAM_TEXT, 'Outcome full name'),
+                                    'name'  => new external_value(PARAM_RAW, 'Outcome full name'),
                                     'scale' => new external_value(PARAM_TEXT, 'Scale items')
                                 )
                             ),
diff --git a/enrol/externallib.php b/enrol/externallib.php
index 3d1f03f7450..d0fbaa9453a 100644
--- a/enrol/externallib.php
+++ b/enrol/externallib.php
@@ -460,7 +460,7 @@ class core_enrol_external extends external_api {
                     'id'        => new external_value(PARAM_INT, 'id of course'),
                     'shortname' => new external_value(PARAM_RAW, 'short name of course'),
                     'fullname'  => new external_value(PARAM_RAW, 'long name of course'),
-                    'displayname' => new external_value(PARAM_TEXT, 'course display name for lists.', VALUE_OPTIONAL),
+                    'displayname' => new external_value(PARAM_RAW, 'course display name for lists.', VALUE_OPTIONAL),
                     'enrolledusercount' => new external_value(PARAM_INT, 'Number of enrolled users in this course',
                             VALUE_OPTIONAL),
                     'idnumber'  => new external_value(PARAM_RAW, 'id number of course'),
diff --git a/enrol/tests/externallib_test.php b/enrol/tests/externallib_test.php
index baf1d70a7f9..3a1b1de3b85 100644
--- a/enrol/tests/externallib_test.php
+++ b/enrol/tests/externallib_test.php
@@ -521,6 +521,61 @@ class core_enrol_externallib_testcase extends externallib_advanced_testcase {
         $this->assertEquals(0, $enrolledincourses[0]['lastaccess']); // I can't see this, hidden by global setting.
     }
 
+    /**
+     * Test get_users_courses with mathjax in the name.
+     */
+    public function test_get_users_courses_with_mathjax() {
+        global $DB;
+
+        $this->resetAfterTest(true);
+
+        // Enable MathJax filter in content and headings.
+        $this->configure_filters([
+            ['name' => 'mathjaxloader', 'state' => TEXTFILTER_ON, 'move' => -1, 'applytostrings' => true],
+        ]);
+
+        // Create a course with MathJax in the name and summary.
+        $coursedata = [
+            'fullname'         => 'Course 1 $$(a+b)=2$$',
+            'shortname'         => 'Course 1 $$(a+b)=2$$',
+            'summary'          => 'Lightwork Course 1 description $$(a+b)=2$$',
+            'summaryformat'    => FORMAT_HTML,
+        ];
+
+        $course = self::getDataGenerator()->create_course($coursedata);
+        $context = context_course::instance($course->id);
+
+        // Enrol a student in the course.
+        $student = $this->getDataGenerator()->create_user();
+        $studentroleid = $DB->get_field('role', 'id', ['shortname' => 'student']);
+        $this->getDataGenerator()->enrol_user($student->id, $course->id, $studentroleid);
+
+        $this->setUser($student);
+
+        // Call the external function.
+        $enrolledincourses = core_enrol_external::get_users_courses($student->id, true);
+
+        // We need to execute the return values cleaning process to simulate the web service server.
+        $enrolledincourses = external_api::clean_returnvalue(core_enrol_external::get_users_courses_returns(), $enrolledincourses);
+
+        // Check that the amount of courses is the right one.
+        $this->assertCount(1, $enrolledincourses);
+
+        // Filter the values to compare them with the returned ones.
+        $course->fullname = external_format_string($course->fullname, $context->id);
+        $course->shortname = external_format_string($course->shortname, $context->id);
+        list($course->summary, $course->summaryformat) =
+             external_format_text($course->summary, $course->summaryformat, $context->id, 'course', 'summary', 0);
+
+        // Compare the values.
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $enrolledincourses[0]['fullname']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $enrolledincourses[0]['shortname']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $enrolledincourses[0]['summary']);
+        $this->assertEquals($course->fullname, $enrolledincourses[0]['fullname']);
+        $this->assertEquals($course->shortname, $enrolledincourses[0]['shortname']);
+        $this->assertEquals($course->summary, $enrolledincourses[0]['summary']);
+    }
+
     /**
      * Test get_course_enrolment_methods
      */
diff --git a/lib/external/externallib.php b/lib/external/externallib.php
index c8e08abbb20..7bc8ab6b56a 100644
--- a/lib/external/externallib.php
+++ b/lib/external/externallib.php
@@ -497,7 +497,7 @@ class core_external extends external_api {
                 'value' => new external_value(PARAM_RAW, 'value of the item as it is stored', VALUE_OPTIONAL),
                 'itemid' => new external_value(PARAM_RAW, 'identifier of the updated item', VALUE_OPTIONAL),
                 'edithint' => new external_value(PARAM_NOTAGS, 'hint for editing element', VALUE_OPTIONAL),
-                'editlabel' => new external_value(PARAM_NOTAGS, 'label for editing element', VALUE_OPTIONAL),
+                'editlabel' => new external_value(PARAM_RAW, 'label for editing element', VALUE_OPTIONAL),
                 'type' => new external_value(PARAM_ALPHA, 'type of the element (text, toggle, select)', VALUE_OPTIONAL),
                 'options' => new external_value(PARAM_RAW, 'options of the element, format depends on type', VALUE_OPTIONAL),
                 'linkeverything' => new external_value(PARAM_INT, 'Should everything be wrapped in the edit link or link displayed separately', VALUE_OPTIONAL),
diff --git a/lib/external/tests/external_test.php b/lib/external/tests/external_test.php
index bf43f49b87f..788371afdab 100644
--- a/lib/external/tests/external_test.php
+++ b/lib/external/tests/external_test.php
@@ -199,9 +199,41 @@ class core_external_testcase extends externallib_advanced_testcase {
         $tag = $this->getDataGenerator()->create_tag();
         $res = core_external::update_inplace_editable('core_tag', 'tagname', $tag->id, 'new tag name');
         $res = external_api::clean_returnvalue(core_external::update_inplace_editable_returns(), $res);
+
         $this->assertEquals('new tag name', $res['value']);
     }
 
+    /**
+     * Test update_inplace_editable with mathjax.
+     */
+    public function test_update_inplace_editable_with_mathjax() {
+        $this->resetAfterTest(true);
+        $this->setAdminUser();
+
+        // Enable MathJax filter in content and headings.
+        $this->configure_filters([
+            ['name' => 'mathjaxloader', 'state' => TEXTFILTER_ON, 'move' => -1, 'applytostrings' => true],
+        ]);
+
+        // Create a forum.
+        $course = $this->getDataGenerator()->create_course();
+        $forum = self::getDataGenerator()->create_module('forum', array('course' => $course->id, 'name' => 'forum name'));
+
+        // Change the forum name.
+        $newname = 'New forum name $$(a+b)=2$$';
+        $res = core_external::update_inplace_editable('core_course', 'activityname', $forum->cmid, $newname);
+        $res = external_api::clean_returnvalue(core_external::update_inplace_editable_returns(), $res);
+
+        // Format original data.
+        $context = context_module::instance($forum->cmid);
+        $newname = external_format_string($newname, $context->id);
+        $editlabel = get_string('newactivityname', '', $newname);
+
+        // Check editlabel is the same and has mathjax.
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $res['editlabel']);
+        $this->assertEquals($editlabel, $res['editlabel']);
+    }
+
     public function test_get_user_dates() {
         $this->resetAfterTest();
 
diff --git a/lib/phpunit/classes/util.php b/lib/phpunit/classes/util.php
index 844cc74ba94..94ec4414dbe 100644
--- a/lib/phpunit/classes/util.php
+++ b/lib/phpunit/classes/util.php
@@ -102,7 +102,7 @@ class phpunit_util extends testing_util {
      * @return void
      */
     public static function reset_all_data($detectchanges = false) {
-        global $DB, $CFG, $USER, $SITE, $COURSE, $PAGE, $OUTPUT, $SESSION, $FULLME;
+        global $DB, $CFG, $USER, $SITE, $COURSE, $PAGE, $OUTPUT, $SESSION, $FULLME, $FILTERLIB_PRIVATE;
 
         // Stop any message redirection.
         self::stop_message_redirection();
@@ -202,6 +202,7 @@ class phpunit_util extends testing_util {
         $FULLME = null;
         $ME = null;
         $SCRIPT = null;
+        $FILTERLIB_PRIVATE = null;
 
         // Empty sessison and set fresh new not-logged-in user.
         \core\session\manager::init_empty_session();
diff --git a/message/externallib.php b/message/externallib.php
index 3e101d59c2f..5512c51e49d 100644
--- a/message/externallib.php
+++ b/message/externallib.php
@@ -1255,8 +1255,8 @@ class core_message_external extends external_api {
         return new external_single_structure(
             array(
                 'id' => new external_value(PARAM_INT, 'The conversation id'),
-                'name' => new external_value(PARAM_TEXT, 'The conversation name, if set', VALUE_DEFAULT, null),
-                'subname' => new external_value(PARAM_TEXT, 'A subtitle for the conversation name, if set', VALUE_DEFAULT, null),
+                'name' => new external_value(PARAM_RAW, 'The conversation name, if set', VALUE_DEFAULT, null),
+                'subname' => new external_value(PARAM_RAW, 'A subtitle for the conversation name, if set', VALUE_DEFAULT, null),
                 'imageurl' => new external_value(PARAM_URL, 'A link to the conversation picture, if set', VALUE_DEFAULT, null),
                 'type' => new external_value(PARAM_INT, 'The type of the conversation (1=individual,2=group,3=self)'),
                 'membercount' => new external_value(PARAM_INT, 'Total number of conversation members'),
@@ -1316,7 +1316,7 @@ class core_message_external extends external_api {
             array(
                 'id' => new external_value(PARAM_INT, 'Conversations id'),
                 'type' => new external_value(PARAM_INT, 'Conversation type: private or public'),
-                'name' => new external_value(PARAM_TEXT, 'Multilang compatible conversation name'. VALUE_OPTIONAL),
+                'name' => new external_value(PARAM_RAW, 'Multilang compatible conversation name'. VALUE_OPTIONAL),
                 'timecreated' => new external_value(PARAM_INT, 'The timecreated timestamp for the conversation'),
             ), 'information about conversation', VALUE_OPTIONAL),
             'Conversations between users', VALUE_OPTIONAL
diff --git a/message/tests/externallib_test.php b/message/tests/externallib_test.php
index 1f143991219..eb380251feb 100644
--- a/message/tests/externallib_test.php
+++ b/message/tests/externallib_test.php
@@ -5912,6 +5912,54 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
         $this->assertCount(0, $conversations);
     }
 
+    /**
+     * Test that group conversations containing MathJax don't break the WebService.
+     */
+    public function test_get_conversations_group_with_mathjax() {
+        $this->resetAfterTest(true);
+        $this->setAdminUser();
+
+        // Enable MathJax filter in content and headings.
+        $this->configure_filters([
+            ['name' => 'mathjaxloader', 'state' => TEXTFILTER_ON, 'move' => -1, 'applytostrings' => true],
+        ]);
+
+        // Create some users, a course and a group with a linked conversation.
+        $user1 = self::getDataGenerator()->create_user();
+        $user2 = self::getDataGenerator()->create_user();
+
+        $coursename = 'Course $$(a+b)=2$$';
+        $groupname = 'Group $$(a+b)=2$$';
+        $course1 = $this->getDataGenerator()->create_course(['shortname' => $coursename]);
+
+        $this->getDataGenerator()->enrol_user($user1->id, $course1->id);
+        $this->getDataGenerator()->enrol_user($user2->id, $course1->id);
+        $group1 = $this->getDataGenerator()->create_group([
+            'name' => $groupname,
+            'courseid' => $course1->id,
+            'enablemessaging' => 1,
+        ]);
+
+        // Add users to group1.
+        $this->getDataGenerator()->create_group_member(array('groupid' => $group1->id, 'userid' => $user1->id));
+        $this->getDataGenerator()->create_group_member(array('groupid' => $group1->id, 'userid' => $user2->id));
+
+        // Call the WebService.
+        $result = core_message_external::get_conversations($user1->id, 0, 20, null, false);
+        $result = external_api::clean_returnvalue(core_message_external::get_conversations_returns(), $result);
+        $conversations = $result['conversations'];
+
+        // Format original data.
+        $coursecontext = \context_course::instance($course1->id);
+        $coursename = external_format_string($coursename, $coursecontext->id);
+        $groupname = external_format_string($groupname, $coursecontext->id);
+
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $conversations[0]['name']);
+        $this->assertStringContainsString('<span class="filter_mathjaxloader_equation">', $conversations[0]['subname']);
+        $this->assertEquals($groupname, $conversations[0]['name']);
+        $this->assertEquals($coursename, $conversations[0]['subname']);
+    }
+
     /**
      * Test verifying get_conversations when there are users in a group and/or individual conversation. The reason this
      * test is performed is because we do not need as much data for group conversations (saving DB calls), so we want
diff --git a/mod/assign/externallib.php b/mod/assign/externallib.php
index 907f7fa1552..49320c76680 100644
--- a/mod/assign/externallib.php
+++ b/mod/assign/externallib.php
@@ -593,8 +593,8 @@ class mod_assign_external extends external_api {
         return new external_single_structure(
             array(
                 'id' => new external_value(PARAM_INT, 'course id'),
-                'fullname' => new external_value(PARAM_TEXT, 'course full name'),
-                'shortname' => new external_value(PARAM_TEXT, 'course short name'),
+                'fullname' => new external_value(PARAM_RAW, 'course full name'),
+                'shortname' => new external_value(PARAM_RAW, 'course short name'),
                 'timemodified' => new external_value(PARAM_INT, 'last time modified'),
                 'assignments' => new external_multiple_structure(self::get_assignments_assignment_structure(), 'assignment info')
               ), 'course information object'
diff --git a/mod/forum/externallib.php b/mod/forum/externallib.php
index 23788fd3772..5151d239ef5 100644
--- a/mod/forum/externallib.php
+++ b/mod/forum/externallib.php
@@ -463,7 +463,7 @@ class mod_forum_external extends external_api {
                                 'created' => new external_value(PARAM_INT, 'Creation time'),
                                 'modified' => new external_value(PARAM_INT, 'Time modified'),
                                 'mailed' => new external_value(PARAM_INT, 'Mailed?'),
-                                'subject' => new external_value(PARAM_TEXT, 'The post subject'),
+                                'subject' => new external_value(PARAM_RAW, 'The post subject'),
                                 'message' => new external_value(PARAM_RAW, 'The post message'),
                                 'messageformat' => new external_format_value('message'),
                                 'messagetrust' => new external_value(PARAM_INT, 'Can we trust?'),
@@ -712,7 +712,7 @@ class mod_forum_external extends external_api {
                         new external_single_structure(
                             array(
                                 'id' => new external_value(PARAM_INT, 'Post id'),
-                                'name' => new external_value(PARAM_TEXT, 'Discussion name'),
+                                'name' => new external_value(PARAM_RAW, 'Discussion name'),
                                 'groupid' => new external_value(PARAM_INT, 'Group id'),
                                 'timemodified' => new external_value(PARAM_INT, 'Time modified'),
                                 'usermodified' => new external_value(PARAM_INT, 'The id of the user who last modified'),
@@ -724,7 +724,7 @@ class mod_forum_external extends external_api {
                                 'created' => new external_value(PARAM_INT, 'Creation time'),
                                 'modified' => new external_value(PARAM_INT, 'Time modified'),
                                 'mailed' => new external_value(PARAM_INT, 'Mailed?'),
-                                'subject' => new external_value(PARAM_TEXT, 'The post subject'),
+                                'subject' => new external_value(PARAM_RAW, 'The post subject'),
                                 'message' => new external_value(PARAM_RAW, 'The post message'),
                                 'messageformat' => new external_format_value('message'),
                                 'messagetrust' => new external_value(PARAM_INT, 'Can we trust?'),
@@ -998,7 +998,7 @@ class mod_forum_external extends external_api {
                     new external_single_structure(
                         array(
                             'id' => new external_value(PARAM_INT, 'Post id'),
-                            'name' => new external_value(PARAM_TEXT, 'Discussion name'),
+                            'name' => new external_value(PARAM_RAW, 'Discussion name'),
                             'groupid' => new external_value(PARAM_INT, 'Group id'),
                             'timemodified' => new external_value(PARAM_INT, 'Time modified'),
                             'usermodified' => new external_value(PARAM_INT, 'The id of the user who last modified'),
@@ -1010,7 +1010,7 @@ class mod_forum_external extends external_api {
                             'created' => new external_value(PARAM_INT, 'Creation time'),
                             'modified' => new external_value(PARAM_INT, 'Time modified'),
                             'mailed' => new external_value(PARAM_INT, 'Mailed?'),
-                            'subject' => new external_value(PARAM_TEXT, 'The post subject'),
+                            'subject' => new external_value(PARAM_RAW, 'The post subject'),
                             'message' => new external_value(PARAM_RAW, 'The post message'),
                             'messageformat' => new external_format_value('message'),
                             'messagetrust' => new external_value(PARAM_INT, 'Can we trust?'),
diff --git a/webservice/tests/helpers.php b/webservice/tests/helpers.php
index 4d0287111e1..e30a955ac49 100644
--- a/webservice/tests/helpers.php
+++ b/webservice/tests/helpers.php
@@ -64,6 +64,43 @@ abstract class externallib_advanced_testcase extends advanced_testcase {
         return $roleid;
     }
 
+    /**
+     * Configure some filters for external tests.
+     *
+     * @param array $filters Filters to enable. Each filter should contain:
+     *                           - name: name of the filter.
+     *                           - state: the state of the filter.
+     *                           - move: -1 means up, 0 means the same, 1 means down.
+     *                           - applytostrings: true to apply the filter to content and headings, false for just content.
+     */
+    public static function configure_filters($filters) {
+        global $CFG;
+
+        $filterstrings = false;
+
+        // Enable the filters.
+        foreach ($filters as $filter) {
+            $filter = (array) $filter;
+            filter_set_global_state($filter['name'], $filter['state'], $filter['move']);
+            filter_set_applies_to_strings($filter['name'], $filter['applytostrings']);
+
+            $filterstrings = $filterstrings || $filter['applytostrings'];
+        }
+
+        // Set WS filtering.
+        $wssettings = external_settings::get_instance();
+        $wssettings->set_filter(true);
+
+        // Reset filter caches.
+        $filtermanager = filter_manager::instance();
+        $filtermanager->reset_caches();
+
+        if ($filterstrings) {
+            // Don't strip tags in strings.
+            $CFG->formatstringstriptags = false;
+        }
+    }
+
     /**
      * Unassign a capability to $USER.
      *
diff --git a/webservice/upgrade.txt b/webservice/upgrade.txt
index 6f92dd39f76..b92bbd402de 100644
--- a/webservice/upgrade.txt
+++ b/webservice/upgrade.txt
@@ -3,6 +3,10 @@ information provided here is intended especially for developers.
 
 This information is intended for authors of webservices, not people writing webservice clients.
 
+=== 3.9.3 ===
+
+* The class externallib_advanced_testcase, used in unit tests, has a new function called "configure_filters" to easily configure filters for external functions testing.
+
 === 3.8 ===
 
 * Ajax calls can now specify a cache key. This allows for better caching capabilities on servers. If a cache key