diff --git a/UPGRADING.md b/UPGRADING.md
index 424d98648de..9de98d9f742 100644
--- a/UPGRADING.md
+++ b/UPGRADING.md
@@ -6,7 +6,7 @@ More detailed information on key changes can be found in the [Developer update n
 
 The format of this change log follows the advice given at [Keep a CHANGELOG](https://keepachangelog.com).
 
-## 5.1dev
+## 5.1dev+
 
 ### core
 
@@ -41,6 +41,27 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
   It is no longer necessary to include `lib/ajax/ajaxlib.php` in any code.
 
   For more information see [MDL-86168](https://tracker.moodle.org/browse/MDL-86168)
+- The Behat `::execute()` method now accepts an array-style callable in addition to the string `classname::method` format.
+
+  The following formats are now accepted:
+
+  ```php
+  // String format:
+  $this->execute('behat_general::i_click_on', [...]);
+
+  // Array format:
+  $this->execute([behat_general::class,' i_click_on'], [...]);
+  ```
+
+  For more information see [MDL-86231](https://tracker.moodle.org/browse/MDL-86231)
+- The following classes have been moved into namespaces and now support autoloading:
+
+  | Old class name          | New class name                         |
+  | ---                     | ---                                    |
+  | `\core_xml_parser`      | `\core\xml_parser`                     |
+  | `\xml_format_exception` | `\core\exception\xml_format_exception` |
+
+  For more information see [MDL-86256](https://tracker.moodle.org/browse/MDL-86256)
 
 #### Changed
 
@@ -61,6 +82,15 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
   ```
 
   For more information see [MDL-85897](https://tracker.moodle.org/browse/MDL-85897)
+- The `\core\output\local\dropdown\dialog` class constructor now accepts a `$definition['autoclose']` parameter to define autoclose behaviour of the element
+
+  For more information see [MDL-86015](https://tracker.moodle.org/browse/MDL-86015)
+- The default PHPUnit configuration now enables the following properties, ensuring PHP warnings will cause test failures (restoring pre-PHPUnit version 10 behaviour):
+
+  * `failOnDeprecation`
+  * `failOnWarning`
+
+  For more information see [MDL-86311](https://tracker.moodle.org/browse/MDL-86311)
 
 #### Deprecated
 
@@ -88,6 +118,9 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
 - The `user_preference_allow_ajax_update()` has been removed. It was deprecated without replacement in Moodle 4.3.
 
   For more information see [MDL-86168](https://tracker.moodle.org/browse/MDL-86168)
+- The `xmlize()` method from `lib/xmlize.php` has been deprecated, please instead use the `\core\xml_parser` class
+
+  For more information see [MDL-86256](https://tracker.moodle.org/browse/MDL-86256)
 
 #### Removed
 
@@ -157,6 +190,38 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
 
   For more information see [MDL-85433](https://tracker.moodle.org/browse/MDL-85433)
 
+#### Removed
+
+- Removed block_section_links from Moodle 5.1.
+
+  For more information see [MDL-80556](https://tracker.moodle.org/browse/MDL-80556)
+- Removed block_activity_modules from Moodle 5.1.
+
+  For more information see [MDL-83887](https://tracker.moodle.org/browse/MDL-83887)
+
+### core_comment
+
+#### Added
+
+- The following classes have been renamed and now support autoloading.
+        Existing classes are currently unaffected.
+
+        | Old class name       | New class name                    |
+        | ---                  | ---                               |
+        | `\comment`           | `\core_comment\manager`           |
+        | `\comment_exception` | `\core_comment\comment_exception` |
+
+  For more information see [MDL-86254](https://tracker.moodle.org/browse/MDL-86254)
+
+#### Deprecated
+
+- The `public/comment/locallib.php` file and the `comment_manager` class have been deprecated. All related functionality should now be accessed via the `\core_comment\manager` class.
+
+  For more information see [MDL-86254](https://tracker.moodle.org/browse/MDL-86254)
+- The `public/comment/lib.php` file is now empty and will be removed in Moodle 6.0. Please, do not include in your code anymore.
+
+  For more information see [MDL-86254](https://tracker.moodle.org/browse/MDL-86254)
+
 ### core_course
 
 #### Added
@@ -388,6 +453,14 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
 
   For more information see [MDL-84071](https://tracker.moodle.org/browse/MDL-84071)
 
+### mod_bigbluebuttonbn
+
+#### Added
+
+- Add activity_dates class to BigblueButton module.
+
+  For more information see [MDL-83889](https://tracker.moodle.org/browse/MDL-83889)
+
 ### mod_choice
 
 #### Added
@@ -579,6 +652,12 @@ The format of this change log follows the advice given at [Keep a CHANGELOG](htt
 
   For more information see [MDL-79319](https://tracker.moodle.org/browse/MDL-79319)
 
+#### Deprecated
+
+- The `core:e/text_highlight` and `core:e/text_highlight_picker` icons are deprecated and will be removed in Moodle 6.0. The UX team recommended this change to reduce visual clutter and improve readability. The icons were removed because they didn't indicate status changes, were repetitive across all notifications, and took up space that could be used for more content.
+
+  For more information see [MDL-85146](https://tracker.moodle.org/browse/MDL-85146)
+
 ## 5.0
 
 ### core
diff --git a/public/ai/UPGRADING.md b/public/ai/UPGRADING.md
index 752304915fb..8d3589eb18d 100644
--- a/public/ai/UPGRADING.md
+++ b/public/ai/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_ai (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/auth/UPGRADING.md b/public/auth/UPGRADING.md
index 51f92257f0c..74b81948087 100644
--- a/public/auth/UPGRADING.md
+++ b/public/auth/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_auth (subsystem / plugintype) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/badges/UPGRADING.md b/public/badges/UPGRADING.md
index 1dd53aa8f9b..f57614ef5f4 100644
--- a/public/badges/UPGRADING.md
+++ b/public/badges/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_badges (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/blocks/UPGRADING.md b/public/blocks/UPGRADING.md
index a1fd995a372..cff97dbfd79 100644
--- a/public/blocks/UPGRADING.md
+++ b/public/blocks/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_block (subsystem / plugintype) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Changed
 
@@ -8,6 +8,15 @@
 
   For more information see [MDL-85433](https://tracker.moodle.org/browse/MDL-85433)
 
+### Removed
+
+- Removed block_section_links from Moodle 5.1.
+
+  For more information see [MDL-80556](https://tracker.moodle.org/browse/MDL-80556)
+- Removed block_activity_modules from Moodle 5.1.
+
+  For more information see [MDL-83887](https://tracker.moodle.org/browse/MDL-83887)
+
 ## 5.0
 
 ### Removed
diff --git a/public/blocks/site_main_menu/UPGRADING.md b/public/blocks/site_main_menu/UPGRADING.md
index 49a0c13f061..9c75b195028 100644
--- a/public/blocks/site_main_menu/UPGRADING.md
+++ b/public/blocks/site_main_menu/UPGRADING.md
@@ -1,6 +1,6 @@
 # block_site_main_menu Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/comment/UPGRADING.md b/public/comment/UPGRADING.md
new file mode 100644
index 00000000000..59c0d82c768
--- /dev/null
+++ b/public/comment/UPGRADING.md
@@ -0,0 +1,25 @@
+# core_comment (subsystem) Upgrade notes
+
+## 5.1dev+
+
+### Added
+
+- The following classes have been renamed and now support autoloading.
+        Existing classes are currently unaffected.
+
+        | Old class name       | New class name                    |
+        | ---                  | ---                               |
+        | `\comment`           | `\core_comment\manager`           |
+        | `\comment_exception` | `\core_comment\comment_exception` |
+
+  For more information see [MDL-86254](https://tracker.moodle.org/browse/MDL-86254)
+
+### Deprecated
+
+- The `public/comment/locallib.php` file and the `comment_manager` class have been deprecated. All related functionality should now be accessed via the `\core_comment\manager` class.
+
+  For more information see [MDL-86254](https://tracker.moodle.org/browse/MDL-86254)
+- The `public/comment/lib.php` file is now empty and will be removed in Moodle 6.0. Please, do not include in your code anymore.
+
+  For more information see [MDL-86254](https://tracker.moodle.org/browse/MDL-86254)
+
diff --git a/public/course/UPGRADING.md b/public/course/UPGRADING.md
index 2499c08c8ed..008e2878139 100644
--- a/public/course/UPGRADING.md
+++ b/public/course/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_course (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/course/format/UPGRADING.md b/public/course/format/UPGRADING.md
index d13d710024d..dc6453f1ed7 100644
--- a/public/course/format/UPGRADING.md
+++ b/public/course/format/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_courseformat (subsystem / plugintype) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/course/format/topics/UPGRADING.md b/public/course/format/topics/UPGRADING.md
index f05c58ee7da..5a4235892ff 100644
--- a/public/course/format/topics/UPGRADING.md
+++ b/public/course/format/topics/UPGRADING.md
@@ -1,6 +1,6 @@
 # format_topics Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/course/format/weeks/UPGRADING.md b/public/course/format/weeks/UPGRADING.md
index 482a6fbcf29..0ea2efc4fbf 100644
--- a/public/course/format/weeks/UPGRADING.md
+++ b/public/course/format/weeks/UPGRADING.md
@@ -1,6 +1,6 @@
 # format_weeks Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/grade/UPGRADING.md b/public/grade/UPGRADING.md
index 0ce437edf63..6d510e10846 100644
--- a/public/grade/UPGRADING.md
+++ b/public/grade/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_grades (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/grade/report/grader/UPGRADING.md b/public/grade/report/grader/UPGRADING.md
index 7f5f53f999e..1da6046236f 100644
--- a/public/grade/report/grader/UPGRADING.md
+++ b/public/grade/report/grader/UPGRADING.md
@@ -1,6 +1,6 @@
 # gradereport_grader Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Removed
 
diff --git a/public/grade/report/singleview/UPGRADING.md b/public/grade/report/singleview/UPGRADING.md
index c6b11e3ed73..4133af65388 100644
--- a/public/grade/report/singleview/UPGRADING.md
+++ b/public/grade/report/singleview/UPGRADING.md
@@ -1,6 +1,6 @@
 # gradereport_singleview Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/lib/UPGRADING.md b/public/lib/UPGRADING.md
index 2c3aa037eec..01e037f9168 100644
--- a/public/lib/UPGRADING.md
+++ b/public/lib/UPGRADING.md
@@ -1,6 +1,6 @@
 # core (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
@@ -33,6 +33,27 @@
   It is no longer necessary to include `lib/ajax/ajaxlib.php` in any code.
 
   For more information see [MDL-86168](https://tracker.moodle.org/browse/MDL-86168)
+- The Behat `::execute()` method now accepts an array-style callable in addition to the string `classname::method` format.
+
+  The following formats are now accepted:
+
+  ```php
+  // String format:
+  $this->execute('behat_general::i_click_on', [...]);
+
+  // Array format:
+  $this->execute([behat_general::class,' i_click_on'], [...]);
+  ```
+
+  For more information see [MDL-86231](https://tracker.moodle.org/browse/MDL-86231)
+- The following classes have been moved into namespaces and now support autoloading:
+
+  | Old class name          | New class name                         |
+  | ---                     | ---                                    |
+  | `\core_xml_parser`      | `\core\xml_parser`                     |
+  | `\xml_format_exception` | `\core\exception\xml_format_exception` |
+
+  For more information see [MDL-86256](https://tracker.moodle.org/browse/MDL-86256)
 
 ### Changed
 
@@ -53,6 +74,15 @@
   ```
 
   For more information see [MDL-85897](https://tracker.moodle.org/browse/MDL-85897)
+- The `\core\output\local\dropdown\dialog` class constructor now accepts a `$definition['autoclose']` parameter to define autoclose behaviour of the element
+
+  For more information see [MDL-86015](https://tracker.moodle.org/browse/MDL-86015)
+- The default PHPUnit configuration now enables the following properties, ensuring PHP warnings will cause test failures (restoring pre-PHPUnit version 10 behaviour):
+
+  * `failOnDeprecation`
+  * `failOnWarning`
+
+  For more information see [MDL-86311](https://tracker.moodle.org/browse/MDL-86311)
 
 ### Deprecated
 
@@ -80,6 +110,9 @@
 - The `user_preference_allow_ajax_update()` has been removed. It was deprecated without replacement in Moodle 4.3.
 
   For more information see [MDL-86168](https://tracker.moodle.org/browse/MDL-86168)
+- The `xmlize()` method from `lib/xmlize.php` has been deprecated, please instead use the `\core\xml_parser` class
+
+  For more information see [MDL-86256](https://tracker.moodle.org/browse/MDL-86256)
 
 ### Removed
 
diff --git a/public/message/UPGRADING.md b/public/message/UPGRADING.md
index 9a558f40c28..a9ec1e1bc79 100644
--- a/public/message/UPGRADING.md
+++ b/public/message/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_message (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/mod/bigbluebuttonbn/UPGRADING.md b/public/mod/bigbluebuttonbn/UPGRADING.md
index 2f5d92ca23b..10767835716 100644
--- a/public/mod/bigbluebuttonbn/UPGRADING.md
+++ b/public/mod/bigbluebuttonbn/UPGRADING.md
@@ -1,5 +1,13 @@
 # mod_bigbluebuttonbn Upgrade notes
 
+## 5.1dev+
+
+### Added
+
+- Add activity_dates class to BigblueButton module.
+
+  For more information see [MDL-83889](https://tracker.moodle.org/browse/MDL-83889)
+
 ## 4.5
 
 ### Added
diff --git a/public/mod/choice/UPGRADING.md b/public/mod/choice/UPGRADING.md
index 9cc340ab5ac..63ad44f9573 100644
--- a/public/mod/choice/UPGRADING.md
+++ b/public/mod/choice/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_choice Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/mod/data/UPGRADING.md b/public/mod/data/UPGRADING.md
index e523ed7a2da..b1f795a3bd3 100644
--- a/public/mod/data/UPGRADING.md
+++ b/public/mod/data/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_data Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/mod/forum/UPGRADING.md b/public/mod/forum/UPGRADING.md
index 6f60dded389..6f097d05d17 100644
--- a/public/mod/forum/UPGRADING.md
+++ b/public/mod/forum/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_forum Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Deprecated
 
diff --git a/public/mod/glossary/UPGRADING.md b/public/mod/glossary/UPGRADING.md
index 09b330415df..378905d10e7 100644
--- a/public/mod/glossary/UPGRADING.md
+++ b/public/mod/glossary/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_glossary Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/mod/label/UPGRADING.md b/public/mod/label/UPGRADING.md
index ff7a845541c..f1c64f6028c 100644
--- a/public/mod/label/UPGRADING.md
+++ b/public/mod/label/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_label Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Removed
 
diff --git a/public/mod/lesson/UPGRADING.md b/public/mod/lesson/UPGRADING.md
index 03aee9ef1f8..b9272f80e56 100644
--- a/public/mod/lesson/UPGRADING.md
+++ b/public/mod/lesson/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_lesson Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/mod/qbank/UPGRADING.md b/public/mod/qbank/UPGRADING.md
index 8fd4878581c..d84ed467f28 100644
--- a/public/mod/qbank/UPGRADING.md
+++ b/public/mod/qbank/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_qbank Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Changed
 
diff --git a/public/mod/quiz/UPGRADING.md b/public/mod/quiz/UPGRADING.md
index f9602d9120a..76bcdb91901 100644
--- a/public/mod/quiz/UPGRADING.md
+++ b/public/mod/quiz/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_quiz Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Deprecated
 
diff --git a/public/mod/scorm/UPGRADING.md b/public/mod/scorm/UPGRADING.md
index e7a941dcaec..c1f7ab37482 100644
--- a/public/mod/scorm/UPGRADING.md
+++ b/public/mod/scorm/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_scorm Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/mod/wiki/UPGRADING.md b/public/mod/wiki/UPGRADING.md
index 820b94fd569..f01cee219be 100644
--- a/public/mod/wiki/UPGRADING.md
+++ b/public/mod/wiki/UPGRADING.md
@@ -1,6 +1,6 @@
 # mod_wiki Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/question/UPGRADING.md b/public/question/UPGRADING.md
index f62892241f7..94a9f56f1bf 100644
--- a/public/question/UPGRADING.md
+++ b/public/question/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_question (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/question/type/multichoice/UPGRADING.md b/public/question/type/multichoice/UPGRADING.md
index 95466b5cbf2..05da7fa50a0 100644
--- a/public/question/type/multichoice/UPGRADING.md
+++ b/public/question/type/multichoice/UPGRADING.md
@@ -1,6 +1,6 @@
 # qtype_multichoice Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Changed
 
diff --git a/public/report/progress/UPGRADING.md b/public/report/progress/UPGRADING.md
index a5ffe108482..e5388796015 100644
--- a/public/report/progress/UPGRADING.md
+++ b/public/report/progress/UPGRADING.md
@@ -1,6 +1,6 @@
 # report_progress Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Changed
 
diff --git a/public/reportbuilder/UPGRADING.md b/public/reportbuilder/UPGRADING.md
index 3da362fea81..31161fdf9bf 100644
--- a/public/reportbuilder/UPGRADING.md
+++ b/public/reportbuilder/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_reportbuilder (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
diff --git a/public/theme/UPGRADING.md b/public/theme/UPGRADING.md
index 2f58016eb77..5c41829e5d7 100644
--- a/public/theme/UPGRADING.md
+++ b/public/theme/UPGRADING.md
@@ -1,6 +1,6 @@
 # theme (plugin type) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Deprecated
 
diff --git a/public/theme/boost/UPGRADING.md b/public/theme/boost/UPGRADING.md
index f2ae6203540..55e65d1517d 100644
--- a/public/theme/boost/UPGRADING.md
+++ b/public/theme/boost/UPGRADING.md
@@ -1,6 +1,6 @@
 # theme_boost Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added
 
@@ -8,6 +8,12 @@
 
   For more information see [MDL-79319](https://tracker.moodle.org/browse/MDL-79319)
 
+### Deprecated
+
+- The `core:e/text_highlight` and `core:e/text_highlight_picker` icons are deprecated and will be removed in Moodle 6.0. The UX team recommended this change to reduce visual clutter and improve readability. The icons were removed because they didn't indicate status changes, were repetitive across all notifications, and took up space that could be used for more content.
+
+  For more information see [MDL-85146](https://tracker.moodle.org/browse/MDL-85146)
+
 ## 5.0
 
 ### Changed
diff --git a/public/user/UPGRADING.md b/public/user/UPGRADING.md
index f0f88d19e6e..5d0384fbc17 100644
--- a/public/user/UPGRADING.md
+++ b/public/user/UPGRADING.md
@@ -1,6 +1,6 @@
 # core_user (subsystem) Upgrade notes
 
-## 5.1dev
+## 5.1dev+
 
 ### Added