diff --git a/.github/workflows/fetch_dialect_ardupilotmega.yml b/.github/workflows/fetch_dialect_ardupilotmega.yml
new file mode 100644
index 00000000000..4375a05cad5
--- /dev/null
+++ b/.github/workflows/fetch_dialect_ardupilotmega.yml
@@ -0,0 +1,50 @@
+name: Fetch ardupilotmega dialects from downstream
+on:
+  workflow_dispatch:
+
+jobs:
+  copy_and_push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout this repo
+        uses: actions/checkout@v4
+        with:
+          repository: mavlink/mavlink
+
+      - name: Download source file(s)
+        run: |
+          curl -L https://raw.githubusercontent.com/ArduPilot/mavlink/master/message_definitions/v1.0/ardupilotmega.xml -o ardupilotmega.xml
+          curl -L https://raw.githubusercontent.com/ArduPilot/mavlink/master/message_definitions/v1.0/loweheiser.xml -o loweheiser.xml
+          
+      - name: Check for changes
+        id: check-changes
+        run: |
+          git status --porcelain | grep -q "^??"  # Check for untracked files
+          if [ $? -eq 0 ]; then
+            echo "No changes detected in the repository. Skipping commit and PR creation."
+          else
+            echo "Changes detected. Proceeding with commit and PR creation."
+          fi
+
+      - name: Copy file (if changes detected)
+        run: |
+          mv -f ardupilotmega.xml message_definitions/v1.0/
+          mv -f loweheiser.xml message_definitions/v1.0/
+        if: steps.check-changes.conclusion == 'success'  # Check for success in previous step
+
+      - name: Add and commit changes (if changes detected)
+        run: |
+          git config --global user.name "${{ secrets.PX4BUILDBOT_USER }}"
+          git config --global user.email "${{ secrets.PX4BUILDBOT_EMAIL }}"
+          git add message_definitions/v1.0/ardupilotmega.xml
+          git add message_definitions/v1.0/loweheiser.xml
+          git commit -a -m "ardupilotmega dialects from ArduPilot/mavlink: `date`"
+        if: steps.check-changes.conclusion == 'success'  # Check for success in previous step
+
+      - name: Create Pull Request (if changes detected)
+        uses: peter-evans/create-pull-request@v7
+        with:
+          title: "[BOT] Add ardupilotmega dialects from ArduPilot/mavlink"
+          body: "ardupilotmega.xml / loweheiser.xml copied from the ArduPilot/mavlink repository."
+          target: master
+        if: steps.check-changes.conclusion == 'success'  # Check for success in previous step
diff --git a/doc/mavlink_xml_to_markdown.py b/doc/mavlink_xml_to_markdown.py
index f78cbd83628..8fce09ba12b 100644
--- a/doc/mavlink_xml_to_markdown.py
+++ b/doc/mavlink_xml_to_markdown.py
@@ -265,7 +265,7 @@ def getMarkdown(self):
     def get_top_level_docs(self, filename):
         # Inject top level heading and other details.
         # print('FILENAME (prefix): %s' % filename)
-        insert_text = '<!-- THIS FILE IS AUTO-GENERATED: https://github.com/mavlink/mavlink/blob/master/doc/mavlink_xml_to_markdown.py -->\n\n'
+        insert_text = '<!-- THIS FILE IS AUTO-GENERATED: https://github.com/mavlink/mavlink/blob/master/doc/mavlink_xml_to_markdown.py -->\n'
         if filename == 'common':
             insert_text += """
 # MAVLINK Common Message Set (common.xml)
@@ -284,7 +284,9 @@ def get_top_level_docs(self, filename):
 
 The message set is defined in [minimal.xml](https://github.com/mavlink/mavlink/blob/master/message_definitions/v1.0/minimal.xml) and is managed by the MAVLink project.
 
-> **Tip** The minimal set is included (imported into) other xml definition files, including the [MAVLink Common Message Set (common.xml)](minimal.md).
+::: tip
+The minimal set is included (imported into) other xml definition files, including the [MAVLink Common Message Set (common.xml)](minimal.md).
+:::
 
 """
         elif filename == 'standard':
@@ -326,12 +328,13 @@ def get_top_level_docs(self, filename):
 - Systems based on these dialects can co-exist on the same MAVLink network.
 - A Ground Station might (optionally) use libraries generated from **all.xml** to communicate using any of the dialects.
 
-> **Warning**
->
-> - New dialect files in the official repository must be added to **all.xml** and restrict themselves to using ids in their own allocated range.
-> - Dialects should push changes to mavlink/mavlink in order to avoid potential clashes from changes to other dialects.
->
-> A few older dialects are not included because these operate in completely closed networks or because they are only used for tests.
+::: warning
+
+- New dialect files in the official repository must be added to **all.xml** and restrict themselves to using ids in their own allocated range.
+- Dialects should push changes to mavlink/mavlink in order to avoid potential clashes from changes to other dialects.
+
+A few older dialects are not included because these operate in completely closed networks or because they are only used for tests.
+:::
 
 This topic is a human-readable form of the XML definition file: [all.xml](https://github.com/mavlink/mavlink/blob/master/message_definitions/v1.0/all.xml).
 """
@@ -340,21 +343,24 @@ def get_top_level_docs(self, filename):
             insert_text += """
 # Dialect: ArduPilotMega
 
-> **Warning** [ardupilotmega.xml](https://github.com/ArduPilot/mavlink/blob/master/message_definitions/v1.0/ardupilotmega.xml) contains the accurate and up-to-date documentation for this dialect.
-> The documentation below may not be accurate if the dialect owner has not pushed changes.
+::: warning
+[ardupilotmega.xml](https://github.com/ArduPilot/mavlink/blob/master/message_definitions/v1.0/ardupilotmega.xml) contains the documentation for this dialect as used by the ArduPilot flight stack.
+The documentation here may not be a precise match if, for example, changes have not been pushed by the owner.
+:::
 
-These messages define the [ArduPilot](http://ardupilot.org) specific dialect (as pushed to the [mavlink/mavlink](https://github.com/mavlink/mavlink) GitHub repository by the dialect owner).
+These messages define the [ArduPilot](http://ardupilot.org) specific dialect.
 
 This topic is a human-readable form of the XML definition file: [ardupilotmega.xml](https://github.com/mavlink/mavlink/blob/master/message_definitions/v1.0/ardupilotmega.xml).
-
     """
 
         elif filename == 'cubepilot':
             insert_text += """
 # Dialect: cubepilot
 
-> **Warning** [cubepilot.xml](https://github.com/CubePilot/mavlink/blob/master/message_definitions/v1.0/cubepilot.xml) contains the accurate and up-to-date documentation for this dialect.
-> The documentation below may not be accurate if the dialect owner has not pushed changes.
+::: warning
+[cubepilot.xml](https://github.com/CubePilot/mavlink/blob/master/message_definitions/v1.0/cubepilot.xml) contains the accurate and up-to-date documentation for this dialect.
+The documentation here may not be a precise match if, for example, changes have not been pushed by the owner.
+:::
 
 These messages define the [CubePilot](http://www.cubepilot.com) specific dialect (as pushed to the [mavlink/mavlink](https://github.com/mavlink/mavlink) GitHub repository by the dialect owner).
 
@@ -369,18 +375,22 @@ def get_top_level_docs(self, filename):
             insert_text += f"""
 # Dialect: {dialectName}
 
-> **Warning** This topic documents the version of the dialect file in the [mavlink/mavlink](https://github.com/mavlink/mavlink) Github repository, which may not be up to date with the file in the source repository (it is up to the dialect owner to push changes when needed).
-> The source repo should be listed in the comments at the top of the XML definition file listed below (but may not be).
+::: warning
+This topic documents the version of the dialect file in the [mavlink/mavlink](https://github.com/mavlink/mavlink) Github repository, which may not be up to date with the file in the source repository (it is up to the dialect owner to push changes when needed).
+The source repo should be listed in the comments at the top of the XML definition file listed below (but may not be).
+:::
 
 This topic is a human-readable form of the XML definition file: [{filenameXML}](https://github.com/mavlink/mavlink/blob/master/message_definitions/v1.0/{filenameXML}).
 """
         insert_text += """
-
 <span id="mav2_extension_field"></span>
 
-> **Note**
-> - MAVLink 2 [extension fields](../guide/define_xml_element.md#message_extensions) are displayed in blue.
-> - Entities from dialects are displayed only as headings (with link to original)
+::: info
+
+- MAVLink 2 [extension fields](../guide/define_xml_element.md#message_extensions) are displayed in blue.
+- Entities from dialects are displayed only as headings (with link to original)
+
+:::
 
 <style>
 span.ext {
@@ -700,9 +710,8 @@ def __init__(self, soup, basename):
 
     def getMarkdown(self, currentDialect):
         """Return markdown for an enum entry"""
-        deprString = f"{self.deprecated.getMarkdown()}" if self.deprecated else ""
-        if self.wip:
-            print(f"TODO: WIP in Enum Entry: {self.name}")
+        deprString = f"<br>{self.deprecated.getMarkdown()}" if self.deprecated else ""
+        wipString = f"<br>{self.wip.getMarkdown()}" if self.wip else ""
         importedNote = ""
         if self.basename is not currentDialect:
             importedNote = " — \[from: [{self.basename}](../messages/{self.basename}.md#{self.name})\]"
@@ -711,7 +720,7 @@ def getMarkdown(self, currentDialect):
                 f"TODO/Debug: Check rendering - imported merged enum value {self.name}")
         desc = fix_add_implicit_links_items(tidyDescription(
             self.description, 'table')) if self.description else ""
-        string = f"<a id='{self.name}'></a>{self.value} | [{self.name}](#{self.name}) | {desc}{importedNote}{deprString} \n"
+        string = f"<a id='{self.name}'></a>{self.value} | [{self.name}](#{self.name}) | {desc}{importedNote}{wipString}{deprString} \n"
         return string
 
 
@@ -1117,7 +1126,7 @@ def generateDocs(self, output_dir="."):
 
     def generateIndexDoc(self, output_dir="."):
         # File for index
-        index_file_name = "README.md"
+        index_file_name = "index.md"
 
         # Create outputdir if it does not exist
         if not os.path.exists(output_dir):
@@ -1126,60 +1135,107 @@ def generateIndexDoc(self, output_dir="."):
 
         #initialise text for index file.
         index_text="""<!-- THIS FILE IS AUTO-GENERATED FROM XML: https://github.com/mavlink/mavlink/blob/master/doc/mavlink_xml_to_markdown.py (Do not update mavlink-devguide) -->
-# XML Definition Files & Dialects
 
-MAVLink definitions files can be found in [mavlink/message definitions](https://github.com/mavlink/mavlink/blob/master/message_definitions/).
-These can roughly be divided into:
+# MAVLink-Standard Definitions
 
-- [Standard definitions](#standard-definitions) - core definitions shared by many flight stacks
-- [Test definitions](#test-definitions) - definitions to support testing and validation
-- [Dialects](#dialects) - *protocol-* and *vendor-specific* messages, enums and commands
+The following XML definition files are part of the standard set that are managed by this project.
+They contain messages, commands, and enums that are expected to be used in multiple flight stacks and ground stations:
 
-## Standard Definitions
+- [common.xml](common.md) - the set of entities that have been implemented in at least one core flight stack (and including those in `standard.xml` and `common.xml`).
 
-The following XML definition files are considered standard/core (i.e. not dialects):
+  ::: tip
+  Most developers should use this set of definitions.
+  :::
 
-- [minimal.xml](minimal.md) - the minimum set of entities (messages, enums, MAV_CMD) required to set up a MAVLink network.
-- [standard.xml](standard.md) - the standard set of entities that are implemented by almost all flight stacks (at least 2, in a compatible way).
-  This `includes` [minimal.xml](minimal.md).
-- [common.xml](common.md) - the set of entities that have been implemented in at least one core flight stack.
-  This `includes` [standard.xml](minimal.md)
+- [standard.xml](standard.md) — the standard set of entities that are implemented by at least two core flight stacks, in a compatible way.
+- [minimal.xml](minimal.md) — the minimum set of entities (messages, enums, MAV_CMD) required to set up a MAVLink network.
 
-> **Note** We are still working towards moving the truly standard entities from **common.xml** to **standard.xml**
-  Currently you should include [common.xml](common.md)
+::: info
+See [Dialects & Test Definitions](dialects.md) for flight-stack specific XML definitions.
+:::
 
-In addition:
+## Development Definitions
 
-- [development.xml](development.md) - XML definitions that are _proposed_ for inclusion in the standard definitions.
-   These are work in progress.
+The following definitions are being considered for inclusion in the standard definitions.
+They are a "work in progress" and should not be used in released software.
 
-## Test Definitions
+- [development.xml](development.md) — XML definitions that are _proposed_ for inclusion in the standard definitions.
+- Any standard definitions that have `<wip />` tags.
 
-The following definitions are used for testing and dialect validation:
+## See Also
+
+- [Dialects & Test Definitions](dialects.md)
+- [XSD schema](../guide/xml_schema.md)
+- [mavlink/message_definitions](https://github.com/mavlink/mavlink/blob/master/message_definitions/) - Source of all XML definition files
+
+"""
+        #Write the index
+        with open(index_file_name, 'w') as content_file:
+            print(f"Generating: {index_file_name}")
+            content_file.write(index_text)
+
+    def generateDialectDoc(self, output_dir="."):
+        # File for index
+        file_name = "dialects.md"
+
+        # Create outputdir if it does not exist
+        if not os.path.exists(output_dir):
+            os.makedirs(output_dir)
+        file_name = f"{output_dir}{file_name}"
+
+        #initialise text for index file.
+        dialect_text="""<!-- THIS FILE IS AUTO-GENERATED FROM XML: https://github.com/mavlink/mavlink/blob/master/doc/mavlink_xml_to_markdown.py (Do not update mavlink-devguide) -->
+
+# Dialects & Test Definitions
 
-- [all.xml](all.md) - This includes all other XML files, and is used to verify that there are no ID clashes (and can potentially be used by GCS to communicate with any core dialect).
-- [test.xml](test.md) - Test XML definition file.
+## Dialects
 
-## Dialects  {#dialects}
+MAVLink _dialects_ are XML definition files that define _protocol-_ and _vendor-specific_ messages, enums and commands.
 
-MAVLink *dialects* are XML definition files that define *protocol-* and *vendor-specific* messages, enums and commands.
+::: warning
+Dialects are not managed by this project!
 
-> **Note** Vendor forks of MAVLink may contain XML entities that have not yet been pushed into the main repository (and will not be documented).
+- They are typically used in only one particular flight stack, and are managed by that flight stack.
+  The XML usually includes owner information as a header comment.
+- Vendor forks of MAVLink may contain XML entities that have not yet been pushed into the main repository (and will not be documented).
 
-Dialects may *include* other MAVLink XML files, which may in turn contain other XML files (up to 5 levels of XML file nesting are allowed - see `MAXIMUM_INCLUDE_FILE_NESTING` in [mavgen.py](https://github.com/ArduPilot/pymavlink/blob/master/generator/mavgen.py#L44)).
-A typical pattern is for a dialect to include [common.xml](../messages/common.md) (containing the *MAVLink standard definitions*), extending it with vendor or protocol specific messages.
+:::
 
 The dialect definitions are:
 
 """
 
         for xmlfile in self.xml_dialects.keys():
-            index_text+=f"- [{xmlfile}.xml]({xmlfile}.md)\n"
+            if xmlfile not in ['common','standard', 'minimal', 'development', 'all', 'test', 'python_array_test']:
+                # Is a dialect
+                dialect_text+=f"- [{xmlfile}.xml]({xmlfile}.md)\n"
+
+        dialect_text+="""
+Note that dialects may `include` [MAVLink-Standard Definitions](index.md) or other dialects.
+Up to 5 levels of XML file nesting are allowed - see `MAXIMUM_INCLUDE_FILE_NESTING` in [mavgen.py](https://github.com/ArduPilot/pymavlink/blob/master/generator/mavgen.py#L44).
+A typical pattern is for a dialect to include [common.xml](../messages/common.md) (containing the _MAVLink standard definitions_), extending it with vendor or protocol specific messages.
+
+## Test Definitions
+
+The following definitions are used for testing and dialect validation:
+
+- [all.xml](all.md) — This includes all other XML files, and is used to verify that there are no ID clashes (and can potentially be used by GCS to communicate with any core dialect).
+- [test.xml](test.md) — Test XML definition file.
+- [python_array_test.xml](python_array_test.md) — Test XML definition file for arrays.
+
+## See Also
+
+- [MAVLink-Standard Definitions](index.md)
+- [XSD schema](../guide/xml_schema.md)
+- [mavlink/message_definitions](https://github.com/mavlink/mavlink/blob/master/message_definitions/) - Source of all XML definition files
+
+"""
 
         #Write the index
-        with open(index_file_name, 'w') as content_file:
-            print(f"Generating: {index_file_name}")
-            content_file.write(index_text)
+        with open(file_name, 'w') as content_file:
+            print(f"Generating: {file_name}")
+            content_file.write(dialect_text)
+
 
 
     def expand_includes(self):
@@ -1323,7 +1379,7 @@ def main():
 
     files.generateDocs(args.output)
     files.generateIndexDoc(args.output)
-
+    files.generateDialectDoc(args.output)
 
 if __name__ == "__main__":
     main()
diff --git a/message_definitions/v1.0/ardupilotmega.xml b/message_definitions/v1.0/ardupilotmega.xml
index 9743ef1024b..451adda538c 100644
--- a/message_definitions/v1.0/ardupilotmega.xml
+++ b/message_definitions/v1.0/ardupilotmega.xml
@@ -4,6 +4,7 @@
   <!-- Vendors -->
   <include>uAvionix.xml</include>
   <include>icarous.xml</include>
+  <include>loweheiser.xml</include>
   <include>cubepilot.xml</include>
   <include>csAirLink.xml</include>
   <dialect>2</dialect>
@@ -22,6 +23,7 @@
     <enum name="HEADING_TYPE">
       <entry value="0" name="HEADING_TYPE_COURSE_OVER_GROUND"/>
       <entry value="1" name="HEADING_TYPE_HEADING"/>
+      <entry value="2" name="HEADING_TYPE_DEFAULT"/>
     </enum>
     <!-- ardupilot specific MAV_CMD_* commands -->
     <enum name="MAV_CMD">
@@ -285,8 +287,8 @@
         <param index="2" label="timeout" units="s">timeout for operation in seconds. Zero means no timeout (0 to 255)</param>
         <param index="3" label="arg1">argument1.</param>
         <param index="4" label="arg2">argument2.</param>
-        <param index="5">Empty</param>
-        <param index="6">Empty</param>
+        <param index="5" label="arg3">argument3.</param>
+        <param index="6" label="arg4">argument4.</param>
         <param index="7">Empty</param>
       </entry>
       <entry value="42703" name="MAV_CMD_NAV_ATTITUDE_TIME" hasLocation="false" isDestination="false">
@@ -313,7 +315,7 @@
         <description>Change target altitude at a given rate. This slews the vehicle at a controllable rate between it's previous altitude and the new one. (affects GUIDED only. Outside GUIDED, aircraft ignores these commands. Designed for onboard companion-computer command-and-control, not normally operator/GCS control.)</description>
         <param index="1">Empty</param>
         <param index="2">Empty</param>
-        <param index="3" label="alt rate-of-change" units="m/s/s" minValue="0">Rate of change, toward new altitude. 0 for maximum rate change. Positive numbers only, as negative numbers will not converge on the new target alt.</param>
+        <param index="3" label="alt rate-of-change" units="m/s" minValue="0">Rate of change, toward new altitude. 0 for maximum rate change. Positive numbers only, as negative numbers will not converge on the new target alt.</param>
         <param index="4">Empty</param>
         <param index="5">Empty</param>
         <param index="6">Empty</param>
@@ -330,6 +332,16 @@
         <param index="7">Empty</param>
       </entry>
       <!-- 43003 MAV_CMD_EXTERNAL_POSITION_ESTIMATE moved to common.xml -->
+      <entry value="43005" name="MAV_CMD_SET_HAGL" hasLocation="false" isDestination="false">
+        <description>Provide a value for height above ground level. This can be used for things like fixed wing and VTOL landing.</description>
+        <param index="1" label="hagl" units="m">Height above ground level.</param>
+        <param index="2" label="accuracy" units="m">estimated one standard deviation accuracy of the measurement. Set to NaN if not known.</param>
+        <param index="3" label="timeout" units="s">Timeout for this data. The flight controller should only consider this data valid within the timeout window.</param>
+        <param index="4">Empty</param>
+        <param index="5">Empty</param>
+        <param index="6">Empty</param>
+        <param index="7">Empty</param>
+      </entry>
     </enum>
     <enum name="SCRIPTING_CMD">
       <entry value="0" name="SCRIPTING_CMD_REPL_START">
@@ -345,6 +357,32 @@
         <description>Stop execution of scripts and restart.</description>
       </entry>
     </enum>
+    <enum name="SECURE_COMMAND_OP">
+      <entry value="0" name="SECURE_COMMAND_GET_SESSION_KEY">
+        <description>Get an 8 byte session key which is used for remote secure updates which operate on flight controller data such as bootloader public keys. Return data will be 8 bytes on success. The session key remains valid until either the flight controller reboots or another SECURE_COMMAND_GET_SESSION_KEY is run.</description>
+      </entry>
+      <entry value="1" name="SECURE_COMMAND_GET_REMOTEID_SESSION_KEY">
+        <description>Get an 8 byte session key which is used for remote secure updates which operate on RemoteID module data. Return data will be 8 bytes on success. The session key remains valid until either the remote ID module reboots or another SECURE_COMMAND_GET_REMOTEID_SESSION_KEY is run.</description>
+      </entry>
+      <entry value="2" name="SECURE_COMMAND_REMOVE_PUBLIC_KEYS">
+        <description>Remove range of public keys from the bootloader. Command data consists of two bytes, first byte if index of first public key to remove. Second byte is the number of keys to remove. If all keys are removed then secure boot is disabled and insecure firmware can be loaded.</description>
+      </entry>
+      <entry value="3" name="SECURE_COMMAND_GET_PUBLIC_KEYS">
+        <description>Get current public keys from the bootloader. Command data consists of two bytes, first byte is index of first public key to fetch, 2nd byte is number of keys to fetch. Total data needs to fit in data portion of reply (max 6 keys for 32 byte keys). Reply data has the index of the first key in the first byte, followed by the keys. Returned keys may be less than the number of keys requested if there are less keys installed than requested.</description>
+      </entry>
+      <entry value="4" name="SECURE_COMMAND_SET_PUBLIC_KEYS">
+        <description>Set current public keys in the bootloader. Data consists of a one byte public key index followed by the public keys. With 32 byte keys this allows for up to 6 keys to be set in one request. Keys outside of the range that is being set will remain unchanged.</description>
+      </entry>
+      <entry value="5" name="SECURE_COMMAND_GET_REMOTEID_CONFIG">
+        <description>Get config data for remote ID module. This command should be sent to the component ID of the flight controller which will forward it to the RemoteID module either over mavlink or DroneCAN. Data format is specific to the RemoteID implementation, see RemoteID firmware documentation for details.</description>
+      </entry>
+      <entry value="6" name="SECURE_COMMAND_SET_REMOTEID_CONFIG">
+        <description>Set config data for remote ID module. This command should be sent to the component ID of the flight controller which will forward it to the RemoteID module either over mavlink or DroneCAN. Data format is specific to the RemoteID implementation, see RemoteID firmware documentation for details.</description>
+      </entry>
+      <entry value="7" name="SECURE_COMMAND_FLASH_BOOTLOADER">
+        <description>Flash bootloader from local storage. Data is the filename to use for the bootloader. This is intended to be used with MAVFtp to upload a new bootloader to a microSD before flashing.</description>
+      </entry>
+    </enum>
     <!-- AP_Limits Enums -->
     <enum name="LIMITS_STATE">
       <entry value="0" name="LIMITS_INIT">
@@ -387,6 +425,12 @@
       <entry value="2" name="LAND_IMMEDIATELY">
         <description>Flag set when plane is to immediately descend to break altitude and land without GCS intervention. Flag not set when plane is to loiter at Rally point until commanded to land.</description>
       </entry>
+      <entry value="4" name="ALT_FRAME_VALID">
+        <description>True if the following altitude frame value is valid.</description>
+      </entry>
+      <entry value="24" name="ALT_FRAME">
+        <description>2 bit value representing altitude frame. 0: absolute, 1: relative home, 2: relative origin, 3: relative terrain</description>
+      </entry>
     </enum>
     <!-- Camera event types -->
     <enum name="CAMERA_STATUS_TYPES">
@@ -946,6 +990,9 @@
       <entry value="512" name="EKF_PRED_POS_HORIZ_ABS">
         <description>Set if EKF's predicted horizontal position (absolute) estimate is good.</description>
       </entry>
+      <entry value="32768" name="EKF_GPS_GLITCHING">
+        <description>Set if EKF believes the GPS input data is faulty.</description>
+      </entry>
       <entry value="1024" name="EKF_UNINITIALIZED">
         <description>Set if EKF has never been healthy.</description>
       </entry>
@@ -1126,6 +1173,7 @@
   </enums>
   <messages>
     <message id="150" name="SENSOR_OFFSETS">
+      <deprecated since="2022-02" replaced_by="MAG_CAL_REPORT, Accel Parameters, and Gyro Parameters"/>
       <description>Offsets and calibrations values for hardware sensors. This makes it easier to debug the calibration process.</description>
       <field type="int16_t" name="mag_ofs_x">Magnetometer X offset.</field>
       <field type="int16_t" name="mag_ofs_y">Magnetometer Y offset.</field>
@@ -1639,6 +1687,24 @@
       <field type="uint32_t" name="request_id">Request ID - copied from request.</field>
       <field type="uint8_t" name="result">0 for success, anything else is failure code.</field>
     </message>
+    <message id="11004" name="SECURE_COMMAND">
+      <description>Send a secure command. Data should be signed with a private key corresponding with a public key known to the recipient. Signature should be over the concatenation of the sequence number (little-endian format), the operation (little-endian format) the data and the session key. For SECURE_COMMAND_GET_SESSION_KEY the session key should be zero length. The data array consists of the data followed by the signature. The sum of the data_length and the sig_length cannot be more than 220. The format of the data is command specific.</description>
+      <field type="uint8_t" name="target_system">System ID.</field>
+      <field type="uint8_t" name="target_component">Component ID.</field>
+      <field type="uint32_t" name="sequence">Sequence ID for tagging reply.</field>
+      <field type="uint32_t" name="operation" enum="SECURE_COMMAND_OP">Operation being requested.</field>
+      <field type="uint8_t" name="data_length">Data length.</field>
+      <field type="uint8_t" name="sig_length">Signature length.</field>
+      <field type="uint8_t[220]" name="data">Signed data.</field>
+    </message>
+    <message id="11005" name="SECURE_COMMAND_REPLY">
+      <description>Reply from secure command.</description>
+      <field type="uint32_t" name="sequence">Sequence ID from request.</field>
+      <field type="uint32_t" name="operation" enum="SECURE_COMMAND_OP">Operation that was requested.</field>
+      <field type="uint8_t" name="result" enum="MAV_RESULT">Result of command.</field>
+      <field type="uint8_t" name="data_length">Data length.</field>
+      <field type="uint8_t[220]" name="data">Reply data.</field>
+    </message>
     <!-- realtime Adaptive Controller tuning message -->
     <message id="11010" name="ADAP_TUNING">
       <description>Adaptive Controller tuning information.</description>
@@ -1736,7 +1802,6 @@
       <field type="float" name="increment">OSD parameter increment.</field>
     </message>
     <message id="11037" name="OBSTACLE_DISTANCE_3D">
-      <wip/>
       <!-- This message is work-in-progress and it can therefore change, and should NOT be used in stable production environments -->
       <description>Obstacle located as a 3D vector.</description>
       <field type="uint32_t" name="time_boot_ms" units="ms">Timestamp (time since system boot).</field>
@@ -1771,5 +1836,50 @@
       <field type="uint16_t" name="MCU_voltage_min" units="mV">MCU voltage minimum</field>
       <field type="uint16_t" name="MCU_voltage_max" units="mV">MCU voltage maximum</field>
     </message>
+    <message id="11040" name="ESC_TELEMETRY_13_TO_16">
+      <description>ESC Telemetry Data for ESCs 13 to 16, matching data sent by BLHeli ESCs.</description>
+      <field type="uint8_t[4]" name="temperature" units="degC">Temperature.</field>
+      <field type="uint16_t[4]" name="voltage" units="cV">Voltage.</field>
+      <field type="uint16_t[4]" name="current" units="cA">Current.</field>
+      <field type="uint16_t[4]" name="totalcurrent" units="mAh">Total current.</field>
+      <field type="uint16_t[4]" name="rpm" units="rpm">RPM (eRPM).</field>
+      <field type="uint16_t[4]" name="count">count of telemetry packets received (wraps at 65535).</field>
+    </message>
+    <message id="11041" name="ESC_TELEMETRY_17_TO_20">
+      <description>ESC Telemetry Data for ESCs 17 to 20, matching data sent by BLHeli ESCs.</description>
+      <field type="uint8_t[4]" name="temperature" units="degC">Temperature.</field>
+      <field type="uint16_t[4]" name="voltage" units="cV">Voltage.</field>
+      <field type="uint16_t[4]" name="current" units="cA">Current.</field>
+      <field type="uint16_t[4]" name="totalcurrent" units="mAh">Total current.</field>
+      <field type="uint16_t[4]" name="rpm" units="rpm">RPM (eRPM).</field>
+      <field type="uint16_t[4]" name="count">count of telemetry packets received (wraps at 65535).</field>
+    </message>
+    <message id="11042" name="ESC_TELEMETRY_21_TO_24">
+      <description>ESC Telemetry Data for ESCs 21 to 24, matching data sent by BLHeli ESCs.</description>
+      <field type="uint8_t[4]" name="temperature" units="degC">Temperature.</field>
+      <field type="uint16_t[4]" name="voltage" units="cV">Voltage.</field>
+      <field type="uint16_t[4]" name="current" units="cA">Current.</field>
+      <field type="uint16_t[4]" name="totalcurrent" units="mAh">Total current.</field>
+      <field type="uint16_t[4]" name="rpm" units="rpm">RPM (eRPM).</field>
+      <field type="uint16_t[4]" name="count">count of telemetry packets received (wraps at 65535).</field>
+    </message>
+    <message id="11043" name="ESC_TELEMETRY_25_TO_28">
+      <description>ESC Telemetry Data for ESCs 25 to 28, matching data sent by BLHeli ESCs.</description>
+      <field type="uint8_t[4]" name="temperature" units="degC">Temperature.</field>
+      <field type="uint16_t[4]" name="voltage" units="cV">Voltage.</field>
+      <field type="uint16_t[4]" name="current" units="cA">Current.</field>
+      <field type="uint16_t[4]" name="totalcurrent" units="mAh">Total current.</field>
+      <field type="uint16_t[4]" name="rpm" units="rpm">RPM (eRPM).</field>
+      <field type="uint16_t[4]" name="count">count of telemetry packets received (wraps at 65535).</field>
+    </message>
+    <message id="11044" name="ESC_TELEMETRY_29_TO_32">
+      <description>ESC Telemetry Data for ESCs 29 to 32, matching data sent by BLHeli ESCs.</description>
+      <field type="uint8_t[4]" name="temperature" units="degC">Temperature.</field>
+      <field type="uint16_t[4]" name="voltage" units="cV">Voltage.</field>
+      <field type="uint16_t[4]" name="current" units="cA">Current.</field>
+      <field type="uint16_t[4]" name="totalcurrent" units="mAh">Total current.</field>
+      <field type="uint16_t[4]" name="rpm" units="rpm">RPM (eRPM).</field>
+      <field type="uint16_t[4]" name="count">count of telemetry packets received (wraps at 65535).</field>
+    </message>
   </messages>
 </mavlink>
diff --git a/message_definitions/v1.0/common.xml b/message_definitions/v1.0/common.xml
index ef098602398..7eb54fad606 100644
--- a/message_definitions/v1.0/common.xml
+++ b/message_definitions/v1.0/common.xml
@@ -1958,6 +1958,19 @@
         <param index="6" label="Pitch Angle" units="deg" minValue="-180" maxValue="180" default="0">Fixed pitch angle that the camera will hold in oblique mode if the mount is actuated in the pitch axis.</param>
         <param index="7">Empty</param>
       </entry>
+      <entry value="262" name="MAV_CMD_DO_SET_STANDARD_MODE" hasLocation="false" isDestination="false">
+        <description>Enable the specified standard MAVLink mode.
+          If the specified mode is not supported, the vehicle should ACK with MAV_RESULT_FAILED.
+          See https://mavlink.io/en/services/standard_modes.html
+        </description>
+        <param index="1" label="Standard Mode" enum="MAV_STANDARD_MODE">The mode to set.</param>
+        <param index="2" reserved="true" default="0"/>
+        <param index="3" reserved="true" default="0"/>
+        <param index="4" reserved="true" default="0"/>
+        <param index="5" reserved="true" default="0"/>
+        <param index="6" reserved="true" default="0"/>
+        <param index="7" reserved="true" default="NaN"/>
+      </entry>
       <entry value="300" name="MAV_CMD_MISSION_START" hasLocation="false" isDestination="false">
         <description>start running a mission</description>
         <param index="1" label="First Item" minValue="0" increment="1">first_item: the first mission item to run</param>
@@ -2159,7 +2172,6 @@
         <param index="1" label="Tag" minValue="0" increment="1">Target tag to jump to.</param>
         <param index="2" label="Repeat" minValue="0" increment="1">Repeat count.</param>
       </entry>
-      <!-- entry value 900 reserved for MAV_CMD_PARAM_TRANSACTION (development.xml) -->
       <entry value="1000" name="MAV_CMD_DO_GIMBAL_MANAGER_PITCHYAW" hasLocation="false" isDestination="false">
         <description>Set gimbal manager pitch/yaw setpoints (low rate command). It is possible to set combinations of the values below. E.g. an angle as well as a desired angular rate can be used to get to this angle at a certain angular rate, or an angular rate only will result in continuous turning. NaN is to be used to signal unset. Note: only the gimbal manager will react to this command - it will be ignored by a gimbal device. Use GIMBAL_MANAGER_SET_PITCHYAW if you need to stream pitch/yaw setpoints at higher rate. </description>
         <param index="1" label="Pitch angle" units="deg" minValue="-180" maxValue="180">Pitch angle (positive to pitch up, relative to vehicle for FOLLOW mode, relative to world horizon for LOCK mode).</param>
@@ -2860,10 +2872,6 @@
       <entry value="9" name="MAV_RESULT_COMMAND_UNSUPPORTED_MAV_FRAME">
         <description>Command is invalid because a frame is required and the specified frame is not supported.</description>
       </entry>
-      <entry value="10" name="MAV_RESULT_PERMISSION_DENIED">
-        <wip/>
-        <description>Sender is not authorized to control this MAV component. Control may be requested using MAV_CMD_REQUEST_OPERATOR_CONTROL.</description>
-      </entry>
     </enum>
     <enum name="MAV_MISSION_RESULT">
       <description>Result of mission operation (in a MISSION_ACK message).</description>
@@ -3401,6 +3409,18 @@
         <description>Battery is not compatible due to cell configuration (e.g. 5s1p when vehicle requires 6s).</description>
       </entry>
     </enum>
+    <enum name="MAV_FUEL_TYPE">
+      <description>Fuel types for use in FUEL_TYPE. Fuel types specify the units for the maximum, available and consumed fuel, and for the flow rates.</description>
+      <entry value="0" name="MAV_FUEL_TYPE_UNKNOWN">
+        <description>Not specified. Fuel levels are normalized (i.e. maximum is 1, and other levels are relative to 1).</description>
+      </entry>
+      <entry value="1" name="MAV_FUEL_TYPE_LIQUID">
+        <description>A generic liquid fuel. Fuel levels are in millilitres (ml). Fuel rates are in millilitres/second.</description>
+      </entry>
+      <entry value="2" name="MAV_FUEL_TYPE_GAS">
+        <description>A gas tank. Fuel levels are in kilo-Pascal (kPa), and flow rates are in milliliters per second (ml/s).</description>
+      </entry>
+    </enum>
     <enum name="MAV_GENERATOR_STATUS_FLAG" bitmask="true">
       <description>Flags to report status/failure cases for a power generator (used in GENERATOR_STATUS). Note that FAULTS are conditions that cause the generator to fail. Warnings are conditions that require attention before the next use (they indicate the system is not operating properly).</description>
       <entry value="1" name="MAV_GENERATOR_STATUS_FLAG_OFF">
@@ -3827,7 +3847,7 @@
         <description>Camera supports tracking geo status (CAMERA_TRACKING_GEO_STATUS).</description>
       </entry>
       <entry value="4096" name="CAMERA_CAP_FLAGS_HAS_THERMAL_RANGE">
-        <description>Camera supports absolute thermal range (request CAMERA_THERMAL_RANGE with MAV_CMD_REQUEST_MESSAGE) (WIP).</description>
+        <description>Camera supports absolute thermal range (request CAMERA_THERMAL_RANGE with MAV_CMD_REQUEST_MESSAGE).</description>
       </entry>
     </enum>
     <enum name="VIDEO_STREAM_STATUS_FLAGS" bitmask="true">
@@ -3839,7 +3859,7 @@
         <description>Stream is thermal imaging</description>
       </entry>
       <entry value="4" name="VIDEO_STREAM_STATUS_FLAGS_THERMAL_RANGE_ENABLED">
-        <description>Stream can report absolute thermal range (see CAMERA_THERMAL_RANGE). (WIP).</description>
+        <description>Stream can report absolute thermal range (see CAMERA_THERMAL_RANGE).</description>
       </entry>
     </enum>
     <enum name="VIDEO_STREAM_TYPE">
@@ -3966,7 +3986,7 @@
       </entry>
     </enum>
     <enum name="PARAM_ACK">
-      <description>Result from PARAM_EXT_SET message (or a PARAM_SET within a transaction).</description>
+      <description>Result from PARAM_EXT_SET message.</description>
       <entry value="0" name="PARAM_ACK_ACCEPTED">
         <description>Parameter value ACCEPTED and SET</description>
       </entry>
@@ -3977,7 +3997,7 @@
         <description>Parameter failed to set</description>
       </entry>
       <entry value="3" name="PARAM_ACK_IN_PROGRESS">
-        <description>Parameter value received but not yet set/accepted. A subsequent PARAM_ACK_TRANSACTION or PARAM_EXT_ACK with the final result will follow once operation is completed. This is returned immediately for parameters that take longer to set, indicating that the the parameter was received and does not need to be resent.</description>
+        <description>Parameter value received but not yet set/accepted. A subsequent PARAM_EXT_ACK with the final result will follow once operation is completed. This is returned immediately for parameters that take longer to set, indicating that the the parameter was received and does not need to be resent.</description>
       </entry>
     </enum>
     <enum name="CAMERA_MODE">
@@ -5156,6 +5176,102 @@
         <description>Illuminator thermistor failure.</description>
       </entry>
     </enum>
+    <enum name="MAV_STANDARD_MODE">
+      <description>Standard modes with a well understood meaning across flight stacks and vehicle types.
+        For example, most flight stack have the concept of a "return" or "RTL" mode that takes a vehicle to safety, even though the precise mechanics of this mode may differ.
+        The modes supported by a flight stack can be queried using AVAILABLE_MODES and set using MAV_CMD_DO_SET_STANDARD_MODE.
+        The current mode is streamed in CURRENT_MODE.
+        See https://mavlink.io/en/services/standard_modes.html
+      </description>
+      <entry value="0" name="MAV_STANDARD_MODE_NON_STANDARD">
+        <description>Non standard mode.
+          This may be used when reporting the mode if the current flight mode is not a standard mode.
+        </description>
+      </entry>
+      <entry value="1" name="MAV_STANDARD_MODE_POSITION_HOLD">
+        <description>Position mode (manual).
+          Position-controlled and stabilized manual mode.
+          When sticks are released vehicles return to their level-flight orientation and hold both position and altitude against wind and external forces.
+          This mode can only be set by vehicles that can hold a fixed position.
+          Multicopter (MC) vehicles actively brake and hold both position and altitude against wind and external forces.
+          Hybrid MC/FW ("VTOL") vehicles first transition to multicopter mode (if needed) but otherwise behave in the same way as MC vehicles.
+          Fixed-wing (FW) vehicles must not support this mode.
+          Other vehicle types must not support this mode (this may be revisited through the PR process).
+        </description>
+      </entry>
+      <entry value="2" name="MAV_STANDARD_MODE_ORBIT">
+        <description>Orbit (manual).
+          Position-controlled and stabilized manual mode.
+          The vehicle circles around a fixed setpoint in the horizontal plane at a particular radius, altitude, and direction.
+          Flight stacks may further allow manual control over the setpoint position, radius, direction, speed, and/or altitude of the circle, but this is not mandated.
+          Flight stacks may support the [MAV_CMD_DO_ORBIT](https://mavlink.io/en/messages/common.html#MAV_CMD_DO_ORBIT) for changing the orbit parameters.
+          MC and FW vehicles may support this mode.
+          Hybrid MC/FW ("VTOL") vehicles may support this mode in MC/FW or both modes; if the mode is not supported by the current configuration the vehicle should transition to the supported configuration.
+          Other vehicle types must not support this mode (this may be revisited through the PR process).
+        </description>
+      </entry>
+      <entry value="3" name="MAV_STANDARD_MODE_CRUISE">
+        <description>Cruise mode (manual).
+          Position-controlled and stabilized manual mode.
+          When sticks are released vehicles return to their level-flight orientation and hold their original track against wind and external forces.
+          Fixed-wing (FW) vehicles level orientation and maintain current track and altitude against wind and external forces.
+          Hybrid MC/FW ("VTOL") vehicles first transition to FW mode (if needed) but otherwise behave in the same way as MC vehicles.
+          Multicopter (MC) vehicles must not support this mode.
+          Other vehicle types must not support this mode (this may be revisited through the PR process).
+        </description>
+      </entry>
+      <entry value="4" name="MAV_STANDARD_MODE_ALTITUDE_HOLD">
+        <description>Altitude hold (manual).
+          Altitude-controlled and stabilized manual mode.
+          When sticks are released vehicles return to their level-flight orientation and hold their altitude.
+          MC vehicles continue with existing momentum and may move with wind (or other external forces).
+          FW vehicles continue with current heading, but may be moved off-track by wind.
+          Hybrid MC/FW ("VTOL") vehicles behave according to their current configuration/mode (FW or MC).
+          Other vehicle types must not support this mode (this may be revisited through the PR process).
+        </description>
+      </entry>
+      <entry value="5" name="MAV_STANDARD_MODE_SAFE_RECOVERY">
+        <description>Safe recovery mode (auto).
+          Automatic mode that takes vehicle to a predefined safe location via a safe flight path, and may also automatically land the vehicle.
+          This mode is more commonly referred to as RTL and/or or Smart RTL.
+          The precise return location, flight path, and landing behaviour depend on vehicle configuration and type.
+          For example, the vehicle might return to the home/launch location, a rally point, or the start of a mission landing, it might follow a direct path, mission path, or breadcrumb path, and land using a mission landing pattern or some other kind of descent.
+        </description>
+      </entry>
+      <entry value="6" name="MAV_STANDARD_MODE_MISSION">
+        <description>Mission mode (automatic).
+          Automatic mode that executes MAVLink missions.
+          Missions are executed from the current waypoint as soon as the mode is enabled.
+        </description>
+      </entry>
+      <entry value="7" name="MAV_STANDARD_MODE_LAND">
+        <description>Land mode (auto).
+          Automatic mode that lands the vehicle at the current location.
+          The precise landing behaviour depends on vehicle configuration and type.
+        </description>
+      </entry>
+      <entry value="8" name="MAV_STANDARD_MODE_TAKEOFF">
+        <description>Takeoff mode (auto).
+          Automatic takeoff mode.
+          The precise takeoff behaviour depends on vehicle configuration and type.
+        </description>
+      </entry>
+    </enum>
+    <enum name="MAV_MODE_PROPERTY" bitmask="true">
+      <description>Mode properties.
+      </description>
+      <entry value="1" name="MAV_MODE_PROPERTY_ADVANCED">
+        <description>If set, this mode is an advanced mode.
+          For example a rate-controlled manual mode might be advanced, whereas a position-controlled manual mode is not.
+          A GCS can optionally use this flag to configure the UI for its intended users.
+        </description>
+      </entry>
+      <entry value="2" name="MAV_MODE_PROPERTY_NOT_USER_SELECTABLE">
+        <description>If set, this mode should not be added to the list of selectable modes.
+          The mode might still be selected by the FC directly (for example as part of a failsafe).
+        </description>
+      </entry>
+    </enum>
   </enums>
   <messages>
     <message id="1" name="SYS_STATUS">
@@ -5184,7 +5300,7 @@
       <field type="uint32_t" name="time_boot_ms" units="ms">Timestamp (time since system boot).</field>
     </message>
     <message id="4" name="PING">
-      <deprecated since="2011-08" replaced_by="SYSTEM_TIME">to be removed / merged with SYSTEM_TIME</deprecated>
+      <deprecated since="2011-08" replaced_by="TIMESYNC">To be removed / merged with TIMESYNC</deprecated>
       <description>A ping message either requesting or responding to a ping. This allows to measure the system latencies, including serial port, radio modem and UDP connections. The ping microservice is documented at https://mavlink.io/en/services/ping.html</description>
       <field type="uint64_t" name="time_usec" units="us">Timestamp (UNIX Epoch time or time since system boot). The receiving end can infer timestamp format (since 1.1.1970 or since system boot) by checking for the magnitude of the number.</field>
       <field type="uint32_t" name="seq">PING sequence</field>
@@ -5232,7 +5348,6 @@
       <field type="uint32_t" name="custom_mode">The new autopilot-specific mode. This field can be ignored by an autopilot.</field>
     </message>
     <!-- IDs 15-17 reserved for PARAM_VALUE_UNION and other param messages -->
-    <!-- IDs 19 reserved for PARAM_ACK_TRANSACTION (development.xml) -->
     <message id="20" name="PARAM_REQUEST_READ">
       <description>Request to read the onboard parameter with the param_id string id. Onboard parameters are stored as key[const char*] -&gt; value[float]. This allows to send a parameter to any other component (such as the GCS) without the need of previous knowledge of possible parameter names. Thus the same GCS can store different parameters for different autopilots. See also https://mavlink.io/en/services/parameter.html for a full documentation of QGroundControl and IMU code.</description>
       <field type="uint8_t" name="target_system">System ID</field>
@@ -5256,7 +5371,7 @@
     <message id="23" name="PARAM_SET">
       <description>Set a parameter value (write new value to permanent storage).
         The receiving component should acknowledge the new parameter value by broadcasting a PARAM_VALUE message (broadcasting ensures that multiple GCS all have an up-to-date list of all parameters). If the sending GCS did not receive a PARAM_VALUE within its timeout time, it should re-send the PARAM_SET message. The parameter microservice is documented at https://mavlink.io/en/services/parameter.html.
-        PARAM_SET may also be called within the context of a transaction (started with MAV_CMD_PARAM_TRANSACTION). Within a transaction the receiving component should respond with PARAM_ACK_TRANSACTION to the setter component (instead of broadcasting PARAM_VALUE), and PARAM_SET should be re-sent if this is ACK not received.</description>
+      </description>
       <field type="uint8_t" name="target_system">System ID</field>
       <field type="uint8_t" name="target_component">Component ID</field>
       <field type="char[16]" name="param_id">Onboard parameter id, terminated by NULL if the length is less than 16 human-readable chars and WITHOUT null termination (NULL) byte if the length is exactly 16 chars - applications have to provide 16+1 bytes storage if the ID is stored as string</field>
@@ -5280,7 +5395,7 @@
       <field type="int32_t" name="alt_ellipsoid" units="mm">Altitude (above WGS84, EGM96 ellipsoid). Positive for up.</field>
       <field type="uint32_t" name="h_acc" units="mm">Position uncertainty.</field>
       <field type="uint32_t" name="v_acc" units="mm">Altitude uncertainty.</field>
-      <field type="uint32_t" name="vel_acc" units="mm">Speed uncertainty.</field>
+      <field type="uint32_t" name="vel_acc" units="mm/s">Speed uncertainty.</field>
       <field type="uint32_t" name="hdg_acc" units="degE5">Heading / track uncertainty</field>
       <field type="uint16_t" name="yaw" units="cdeg" invalid="0">Yaw in earth frame from north. Use 0 if this GPS does not provide yaw. Use UINT16_MAX if this GPS is configured to provide yaw and is currently unable to provide it. Use 36000 for north.</field>
     </message>
@@ -6177,6 +6292,7 @@
         If the response has `target_system==target_component==0` the remote system has not been updated to use the component IDs and cannot reliably timesync; the requestor may report an error.
         Timestamps are UNIX Epoch time or time since system boot in nanoseconds (the timestamp format can be inferred by checking for the magnitude of the number; generally it doesn't matter as only the offset is used).
         The message sequence is repeated numerous times with results being filtered/averaged to estimate the offset.
+        See also: https://mavlink.io/en/services/timesync.html.
       </description>
       <field type="int64_t" name="tc1" units="ns">Time sync timestamp 1. Syncing: 0. Responding: Timestamp of responding component.</field>
       <field type="int64_t" name="ts1" units="ns">Time sync timestamp 2. Timestamp of syncing component (mirrored in response).</field>
@@ -6325,7 +6441,7 @@
       <field type="int32_t" name="alt_ellipsoid" units="mm">Altitude (above WGS84, EGM96 ellipsoid). Positive for up.</field>
       <field type="uint32_t" name="h_acc" units="mm">Position uncertainty.</field>
       <field type="uint32_t" name="v_acc" units="mm">Altitude uncertainty.</field>
-      <field type="uint32_t" name="vel_acc" units="mm">Speed uncertainty.</field>
+      <field type="uint32_t" name="vel_acc" units="mm/s">Speed uncertainty.</field>
       <field type="uint32_t" name="hdg_acc" units="degE5">Heading / track uncertainty</field>
     </message>
     <message id="125" name="POWER_STATUS">
@@ -7014,7 +7130,7 @@
         set to the sequence number of the final message in the range.</description>
       <field type="uint32_t" name="time_boot_ms" units="ms">Timestamp (time since system boot).</field>
       <field type="uint64_t" name="time_utc" units="us" invalid="0">Timestamp (time since UNIX epoch) in UTC. 0 for unknown.</field>
-      <field type="uint8_t" name="camera_id">Deprecated/unused. Component IDs are used to differentiate multiple cameras.</field>
+      <field type="uint8_t" name="camera_id" default="0" minValue="0" maxValue="6">Camera id of a non-MAVLink camera attached to an autopilot (1-6).  0 if the component is a MAVLink camera (with its own component id). Field name is usually camera_device_id.</field>
       <field type="int32_t" name="lat" units="degE7">Latitude where image was taken</field>
       <field type="int32_t" name="lon" units="degE7">Longitude where capture was taken</field>
       <field type="int32_t" name="alt" units="mm">Altitude (MSL) where image was taken</field>
@@ -7152,8 +7268,6 @@
       <field type="uint8_t" name="camera_device_id" default="0" minValue="0" maxValue="6">Camera id of a non-MAVLink camera attached to an autopilot (1-6).  0 if the component is a MAVLink camera (with its own component id).</field>
     </message>
     <message id="277" name="CAMERA_THERMAL_RANGE">
-      <wip/>
-      <!-- This message is work-in-progress and it can therefore change. It should NOT be used in stable production environments. -->
       <description>Camera absolute thermal range. This can be streamed when the associated VIDEO_STREAM_STATUS `flag` field bit VIDEO_STREAM_STATUS_FLAGS_THERMAL_RANGE_ENABLED is set, but a GCS may choose to only request it for the current active stream. Use MAV_CMD_SET_MESSAGE_INTERVAL to define message interval (param3 indicates the stream id of the current camera, or 0 for all streams, param4 indicates the target camera_device_id for autopilot-attached cameras or 0 for MAVLink cameras).</description>
       <field type="uint32_t" name="time_boot_ms" units="ms">Timestamp (time since system boot).</field>
       <field type="uint8_t" name="stream_id" minValue="1" instance="true">Video Stream ID (1 for first, 2 for second, etc.)</field>
@@ -7582,7 +7696,30 @@
       <field type="uint32_t" name="discharge_maximum_burst_current" units="mA" invalid="0">Maximum pack discharge burst current. 0: field not provided.</field>
       <field type="char[11]" name="manufacture_date" invalid="[0]">Manufacture date (DD/MM/YYYY) in ASCII characters, 0 terminated. All 0: field not provided.</field>
     </message>
-    <!-- id 371 reserved for FUEL_STATUS in development.xml -->
+    <message id="371" name="FUEL_STATUS">
+      <description>Fuel status.
+        This message provides "generic" fuel level information for display in a GCS and for triggering failsafes in an autopilot.
+        The fuel type and associated units for fields in this message are defined in the enum MAV_FUEL_TYPE.
+
+        The reported `consumed_fuel` and `remaining_fuel` must only be supplied if measured: they must not be inferred from the `maximum_fuel` and the other value.
+        A recipient can assume that if these fields are supplied they are accurate.
+        If not provided, the recipient can infer `remaining_fuel` from `maximum_fuel` and `consumed_fuel` on the assumption that the fuel was initially at its maximum (this is what battery monitors assume).
+        Note however that this is an assumption, and the UI should prompt the user appropriately (i.e. notify user that they should fill the tank before boot).
+
+        This kind of information may also be sent in fuel-specific messages such as BATTERY_STATUS_V2.
+        If both messages are sent for the same fuel system, the ids and corresponding information must match.
+
+        This should be streamed (nominally at 0.1 Hz).
+      </description>
+      <field type="uint8_t" name="id" instance="true">Fuel ID. Must match ID of other messages for same fuel system, such as BATTERY_STATUS_V2.</field>
+      <field type="float" name="maximum_fuel">Capacity when full. Must be provided.</field>
+      <field type="float" name="consumed_fuel" invalid="NaN">Consumed fuel (measured). This value should not be inferred: if not measured set to NaN. NaN: field not provided.</field>
+      <field type="float" name="remaining_fuel" invalid="NaN">Remaining fuel until empty (measured). The value should not be inferred: if not measured set to NaN. NaN: field not provided.</field>
+      <field type="uint8_t" name="percent_remaining" units="%" invalid="UINT8_MAX">Percentage of remaining fuel, relative to full. Values: [0-100], UINT8_MAX: field not provided.</field>
+      <field type="float" name="flow_rate" invalid="NaN">Positive value when emptying/using, and negative if filling/replacing. NaN: field not provided.</field>
+      <field type="float" name="temperature" units="K" invalid="NaN">Fuel temperature. NaN: field not provided.</field>
+      <field type="uint32_t" name="fuel_type" enum="MAV_FUEL_TYPE">Fuel type. Defines units for fuel capacity and consumption fields above.</field>
+    </message>
     <message id="372" name="BATTERY_INFO">
       <wip/>
       <description>
@@ -7776,6 +7913,41 @@
       <field type="uint16_t" name="sequence_oldest_available">Oldest Sequence number that is still available after the sequence set in REQUEST_EVENT.</field>
       <field type="uint8_t" name="reason" enum="MAV_EVENT_ERROR_REASON">Error reason.</field>
     </message>
+    <message id="435" name="AVAILABLE_MODES">
+      <description>Information about a flight mode.
+
+        The message can be enumerated to get information for all modes, or requested for a particular mode, using MAV_CMD_REQUEST_MESSAGE.
+        Specify 0 in param2 to request that the message is emitted for all available modes or the specific index for just one mode.
+        The modes must be available/settable for the current vehicle/frame type.
+        Each mode should only be emitted once (even if it is both standard and custom).
+        Note that the current mode should be emitted in CURRENT_MODE, and that if the mode list can change then AVAILABLE_MODES_MONITOR must be emitted on first change and subsequently streamed.
+        See https://mavlink.io/en/services/standard_modes.html
+      </description>
+      <field type="uint8_t" name="number_modes">The total number of available modes for the current vehicle type.</field>
+      <field type="uint8_t" name="mode_index">The current mode index within number_modes, indexed from 1. The index is not guaranteed to be persistent, and may change between reboots or if the set of modes change.</field>
+      <field type="uint8_t" name="standard_mode" enum="MAV_STANDARD_MODE">Standard mode.</field>
+      <field type="uint32_t" name="custom_mode">A bitfield for use for autopilot-specific flags</field>
+      <field type="uint32_t" name="properties" enum="MAV_MODE_PROPERTY">Mode properties.</field>
+      <field type="char[35]" name="mode_name">Name of custom mode, with null termination character. Should be omitted for standard modes.</field>
+    </message>
+    <message id="436" name="CURRENT_MODE">
+      <description>Get the current mode.
+        This should be emitted on any mode change, and broadcast at low rate (nominally 0.5 Hz).
+        It may be requested using MAV_CMD_REQUEST_MESSAGE.
+        See https://mavlink.io/en/services/standard_modes.html
+      </description>
+      <field type="uint8_t" name="standard_mode" enum="MAV_STANDARD_MODE">Standard mode.</field>
+      <field type="uint32_t" name="custom_mode">A bitfield for use for autopilot-specific flags</field>
+      <field type="uint32_t" name="intended_custom_mode" invalid="0">The custom_mode of the mode that was last commanded by the user (for example, with MAV_CMD_DO_SET_STANDARD_MODE, MAV_CMD_DO_SET_MODE or via RC). This should usually be the same as custom_mode. It will be different if the vehicle is unable to enter the intended mode, or has left that mode due to a failsafe condition. 0 indicates the intended custom mode is unknown/not supplied</field>
+    </message>
+    <message id="437" name="AVAILABLE_MODES_MONITOR">
+      <description>A change to the sequence number indicates that the set of AVAILABLE_MODES has changed.
+        A receiver must re-request all available modes whenever the sequence number changes.
+        This is only emitted after the first change and should then be broadcast at low rate (nominally 0.3 Hz) and on change.
+        See https://mavlink.io/en/services/standard_modes.html
+      </description>
+      <field type="uint8_t" name="seq">Sequence number. The value iterates sequentially whenever AVAILABLE_MODES changes (e.g. support for a new mode is added/removed dynamically).</field>
+    </message>
     <message id="440" name="ILLUMINATOR_STATUS">
       <description>Illuminator status</description>
       <field type="uint32_t" name="uptime_ms" units="ms">Time since the start-up of the illuminator in ms</field>
diff --git a/message_definitions/v1.0/development.xml b/message_definitions/v1.0/development.xml
index bc3e16e1407..e9d0a298c3f 100644
--- a/message_definitions/v1.0/development.xml
+++ b/message_definitions/v1.0/development.xml
@@ -5,27 +5,6 @@
   <version>0</version>
   <dialect>0</dialect>
   <enums>
-    <enum name="WIFI_NETWORK_SECURITY">
-      <description>WiFi wireless security protocols.</description>
-      <entry value="0" name="WIFI_NETWORK_SECURITY_UNDEFINED">
-        <description>Undefined or unknown security protocol.</description>
-      </entry>
-      <entry value="1" name="WIFI_NETWORK_SECURITY_OPEN">
-        <description>Open network, no security.</description>
-      </entry>
-      <entry value="2" name="WIFI_NETWORK_SECURITY_WEP">
-        <description>WEP.</description>
-      </entry>
-      <entry value="3" name="WIFI_NETWORK_SECURITY_WPA1">
-        <description>WPA1.</description>
-      </entry>
-      <entry value="4" name="WIFI_NETWORK_SECURITY_WPA2">
-        <description>WPA2.</description>
-      </entry>
-      <entry value="5" name="WIFI_NETWORK_SECURITY_WPA3">
-        <description>WPA3.</description>
-      </entry>
-    </enum>
     <enum name="AIRSPEED_SENSOR_FLAGS" bitmask="true">
       <description>Airspeed sensor flags</description>
       <entry value="0" name="AIRSPEED_SENSOR_UNHEALTHY">
@@ -35,128 +14,6 @@
         <description>True if the data from this sensor is being actively used by the flight controller for guidance, navigation or control.</description>
       </entry>
     </enum>
-    <!-- Transactions for parameter protocol -->
-    <enum name="PARAM_TRANSACTION_TRANSPORT">
-      <description>Possible transport layers to set and get parameters via mavlink during a parameter transaction.</description>
-      <entry value="0" name="PARAM_TRANSACTION_TRANSPORT_PARAM">
-        <description>Transaction over param transport.</description>
-      </entry>
-      <entry value="1" name="PARAM_TRANSACTION_TRANSPORT_PARAM_EXT">
-        <description>Transaction over param_ext transport.</description>
-      </entry>
-    </enum>
-    <enum name="PARAM_TRANSACTION_ACTION">
-      <description>Possible parameter transaction actions.</description>
-      <entry value="0" name="PARAM_TRANSACTION_ACTION_START">
-        <description>Commit the current parameter transaction.</description>
-      </entry>
-      <entry value="1" name="PARAM_TRANSACTION_ACTION_COMMIT">
-        <description>Commit the current parameter transaction.</description>
-      </entry>
-      <entry value="2" name="PARAM_TRANSACTION_ACTION_CANCEL">
-        <description>Cancel the current parameter transaction.</description>
-      </entry>
-    </enum>
-    <enum name="MAV_STANDARD_MODE">
-      <description>Standard modes with a well understood meaning across flight stacks and vehicle types.
-        For example, most flight stack have the concept of a "return" or "RTL" mode that takes a vehicle to safety, even though the precise mechanics of this mode may differ.
-        Modes may be set using MAV_CMD_DO_SET_STANDARD_MODE.
-      </description>
-      <entry value="0" name="MAV_STANDARD_MODE_NON_STANDARD">
-        <description>Non standard mode.
-          This may be used when reporting the mode if the current flight mode is not a standard mode.
-        </description>
-      </entry>
-      <entry value="1" name="MAV_STANDARD_MODE_POSITION_HOLD">
-        <description>Position mode (manual).
-          Position-controlled and stabilized manual mode.
-          When sticks are released vehicles return to their level-flight orientation and hold both position and altitude against wind and external forces.
-          This mode can only be set by vehicles that can hold a fixed position.
-          Multicopter (MC) vehicles actively brake and hold both position and altitude against wind and external forces.
-          Hybrid MC/FW ("VTOL") vehicles first transition to multicopter mode (if needed) but otherwise behave in the same way as MC vehicles.
-          Fixed-wing (FW) vehicles must not support this mode.
-          Other vehicle types must not support this mode (this may be revisited through the PR process).
-        </description>
-      </entry>
-      <entry value="2" name="MAV_STANDARD_MODE_ORBIT">
-        <description>Orbit (manual).
-          Position-controlled and stabilized manual mode.
-          The vehicle circles around a fixed setpoint in the horizontal plane at a particular radius, altitude, and direction.
-          Flight stacks may further allow manual control over the setpoint position, radius, direction, speed, and/or altitude of the circle, but this is not mandated.
-          Flight stacks may support the [MAV_CMD_DO_ORBIT](https://mavlink.io/en/messages/common.html#MAV_CMD_DO_ORBIT) for changing the orbit parameters.
-          MC and FW vehicles may support this mode.
-          Hybrid MC/FW ("VTOL") vehicles may support this mode in MC/FW or both modes; if the mode is not supported by the current configuration the vehicle should transition to the supported configuration.
-          Other vehicle types must not support this mode (this may be revisited through the PR process).
-        </description>
-      </entry>
-      <entry value="3" name="MAV_STANDARD_MODE_CRUISE">
-        <description>Cruise mode (manual).
-          Position-controlled and stabilized manual mode.
-          When sticks are released vehicles return to their level-flight orientation and hold their original track against wind and external forces.
-          Fixed-wing (FW) vehicles level orientation and maintain current track and altitude against wind and external forces.
-          Hybrid MC/FW ("VTOL") vehicles first transition to FW mode (if needed) but otherwise behave in the same way as MC vehicles.
-          Multicopter (MC) vehicles must not support this mode.
-          Other vehicle types must not support this mode (this may be revisited through the PR process).
-        </description>
-      </entry>
-      <entry value="4" name="MAV_STANDARD_MODE_ALTITUDE_HOLD">
-        <description>Altitude hold (manual).
-          Altitude-controlled and stabilized manual mode.
-          When sticks are released vehicles return to their level-flight orientation and hold their altitude.
-          MC vehicles continue with existing momentum and may move with wind (or other external forces).
-          FW vehicles continue with current heading, but may be moved off-track by wind.
-          Hybrid MC/FW ("VTOL") vehicles behave according to their current configuration/mode (FW or MC).
-          Other vehicle types must not support this mode (this may be revisited through the PR process).
-        </description>
-      </entry>
-      <entry value="5" name="MAV_STANDARD_MODE_RETURN_HOME">
-        <description>Return home mode (auto).
-          Automatic mode that returns vehicle to home via a safe flight path.
-          It may also automatically land the vehicle (i.e. RTL).
-          The precise flight path and landing behaviour depend on vehicle configuration and type.
-        </description>
-      </entry>
-      <entry value="6" name="MAV_STANDARD_MODE_SAFE_RECOVERY">
-        <description>Safe recovery mode (auto).
-          Automatic mode that takes vehicle to a predefined safe location via a safe flight path (rally point or mission defined landing) .
-          It may also automatically land the vehicle.
-          The precise return location, flight path, and landing behaviour depend on vehicle configuration and type.
-        </description>
-      </entry>
-      <entry value="7" name="MAV_STANDARD_MODE_MISSION">
-        <description>Mission mode (automatic).
-          Automatic mode that executes MAVLink missions.
-          Missions are executed from the current waypoint as soon as the mode is enabled.
-        </description>
-      </entry>
-      <entry value="8" name="MAV_STANDARD_MODE_LAND">
-        <description>Land mode (auto).
-          Automatic mode that lands the vehicle at the current location.
-          The precise landing behaviour depends on vehicle configuration and type.
-        </description>
-      </entry>
-      <entry value="9" name="MAV_STANDARD_MODE_TAKEOFF">
-        <description>Takeoff mode (auto).
-          Automatic takeoff mode.
-          The precise takeoff behaviour depends on vehicle configuration and type.
-        </description>
-      </entry>
-    </enum>
-    <enum name="MAV_MODE_PROPERTY" bitmask="true">
-      <description>Mode properties.
-      </description>
-      <entry value="1" name="MAV_MODE_PROPERTY_ADVANCED">
-        <description>If set, this mode is an advanced mode.
-          For example a rate-controlled manual mode might be advanced, whereas a position-controlled manual mode is not.
-          A GCS can optionally use this flag to configure the UI for its intended users.
-        </description>
-      </entry>
-      <entry value="2" name="MAV_MODE_PROPERTY_NOT_USER_SELECTABLE">
-        <description>If set, this mode should not be added to the list of selectable modes.
-          The mode might still be selected by the FC directly (for example as part of a failsafe).
-        </description>
-      </entry>
-    </enum>
     <enum name="MAV_BATTERY_STATUS_FLAGS" bitmask="true">
       <description>Battery status flags for fault, health and state indication.</description>
       <entry value="1" name="MAV_BATTERY_STATUS_FLAGS_NOT_READY_TO_USE">
@@ -292,12 +149,6 @@
         <param index="7" label="Altitude/Z">Center point altitude MSL/Z coordinate according to MAV_FRAME. If no MAV_FRAME specified, MAV_FRAME_GLOBAL is assumed.
         INT32_MAX or NaN: Use current vehicle altitude.</param>
       </entry>
-      <entry value="900" name="MAV_CMD_PARAM_TRANSACTION" hasLocation="false" isDestination="false">
-        <description>Request to start or end a parameter transaction. Multiple kinds of transport layers can be used to exchange parameters in the transaction (param, param_ext and mavftp). The command response can either be a success/failure or an in progress in case the receiving side takes some time to apply the parameters.</description>
-        <param index="1" label="Action" enum="PARAM_TRANSACTION_ACTION">Action to be performed (start, commit, cancel, etc.)</param>
-        <param index="2" label="Transport" enum="PARAM_TRANSACTION_TRANSPORT">Possible transport layers to set and get parameters via mavlink during a parameter transaction.</param>
-        <param index="3" label="Transaction ID">Identifier for a specific transaction.</param>
-      </entry>
       <entry value="247" name="MAV_CMD_DO_UPGRADE" hasLocation="false" isDestination="false">
         <description>Request a target system to start an upgrade of one (or all) of its components.
           For example, the command might be sent to a companion computer to cause it to upgrade a connected flight controller.
@@ -311,34 +162,6 @@
         <param index="6">Reserved</param>
         <param index="7">WIP: upgrade progress report rate (can be used for more granular control).</param>
       </entry>
-      <entry value="301" name="MAV_CMD_GROUP_START" hasLocation="false" isDestination="false">
-        <description>Define start of a group of mission items. When control reaches this command a GROUP_START message is emitted.
-          The end of a group is marked using MAV_CMD_GROUP_END with the same group id.
-          Group ids are expected, but not required, to iterate sequentially.
-          Groups can be nested.</description>
-        <param index="1" label="Group ID" minValue="0" maxValue="16777216" increment="1">Mission-unique group id.
-          Group id is limited because only 24 bit integer can be stored in 32 bit float.</param>
-      </entry>
-      <entry value="302" name="MAV_CMD_GROUP_END" hasLocation="false" isDestination="false">
-        <description>Define end of a group of mission items. When control reaches this command a GROUP_END message is emitted.
-          The start of the group is marked is marked using MAV_CMD_GROUP_START with the same group id.
-          Group ids are expected, but not required, to iterate sequentially.
-          Groups can be nested.</description>
-        <param index="1" label="Group ID" minValue="0" maxValue="16777216" increment="1">Mission-unique group id.
-          Group id is limited because only 24 bit integer can be stored in 32 bit float.</param>
-      </entry>
-      <entry value="262" name="MAV_CMD_DO_SET_STANDARD_MODE" hasLocation="false" isDestination="false">
-        <description>Enable the specified standard MAVLink mode.
-          If the mode is not supported the vehicle should ACK with MAV_RESULT_FAILED.
-        </description>
-        <param index="1" label="Standard Mode" enum="MAV_STANDARD_MODE">The mode to set.</param>
-        <param index="2" reserved="true" default="0"/>
-        <param index="3" reserved="true" default="0"/>
-        <param index="4" reserved="true" default="0"/>
-        <param index="5" reserved="true" default="0"/>
-        <param index="6" reserved="true" default="0"/>
-        <param index="7" reserved="true" default="NaN"/>
-      </entry>
       <entry value="550" name="MAV_CMD_SET_AT_S_PARAM" hasLocation="false" isDestination="false">
         <description>Allows setting an AT S command of an SiK radio.
         </description>
@@ -388,11 +211,11 @@
         <param index="6">Empty</param>
         <param index="7">Empty</param>
       </entry>
-      <entry value="43005" name="MAV_CMD_REQUEST_OPERATOR_CONTROL" hasLocation="false" isDestination="false">
+      <entry value="32100" name="MAV_CMD_REQUEST_OPERATOR_CONTROL" hasLocation="false" isDestination="false">
         <description>Request GCS control of a system (or of a specific component in a system).
 
           A controlled system should only accept MAVLink commands and command-like messages that are sent by its controlling GCS, or from other components with the same system id.
-          Commands from other systems should be rejected with MAV_RESULT_PERMISSION_DENIED (except for this command, which may be acknowledged with MAV_RESULT_ACCEPTED if control is granted).
+          Commands from other systems should be rejected with MAV_RESULT_FAILED (except for this command, which may be acknowledged with MAV_RESULT_ACCEPTED if control is granted).
           Command-like messages should be ignored (or rejected if that is supported by their associated protocol).
 
           GCS control of the whole system is managed via a single component that we will refer to here as the "system manager component".
@@ -400,17 +223,18 @@
           Other components in the system should monitor for the CONTROL_STATUS message with this flag, and set their controlling GCS to match its published system id.
           A GCS that wants to control the system should also monitor for the same message and flag, and address the MAV_CMD_REQUEST_OPERATOR_CONTROL to its component id.
           Note that integrators are required to ensure that there is only one system manager component in the system (i.e. one component emitting the message with GCS_CONTROL_STATUS_FLAGS_SYSTEM_MANAGER set).
-   
+
           The MAV_CMD_REQUEST_OPERATOR_CONTROL command is sent by a GCS to the system manager component to request or release control of a system, specifying whether subsequent takeover requests from another GCS are automatically granted, or require permission.
 
           The system manager component should grant control to the GCS if the system does not require takeover permission (or is uncontrolled) and ACK the request with MAV_RESULT_ACCEPTED.
           The system manager component should then stream CONTROL_STATUS indicating its controlling system: all other components with the same system id should monitor this message and set their own controlling GCS to match that of the system manager component.
 
-          If the system manager component cannot grant control (because takeover requires permission), the request should be rejected with MAV_RESULT_PERMISSION_DENIED.
+          If the system manager component cannot grant control (because takeover requires permission), the request should be rejected with MAV_RESULT_FAILED.
           The system manager component should then send this same command to the current owning GCS in order to notify of the request.
-          The owning GCS would ACK with MAV_RESULT_ACCEPTED, and might choose to release control of the vehicle, or re-request control with the takeover bit set to allow permission. 
+          The owning GCS would ACK with MAV_RESULT_ACCEPTED, and might choose to release control of the vehicle, or re-request control with the takeover bit set to allow permission.
+          In case it choses to re-request control with takeover bit set to allow permission, requestor GCS will only have 10 seconds to get control, otherwise owning GCS will re-request control with takeover bit set to disallow permission, and requestor GCS will need repeat the request if still interested in getting control.
           Note that the pilots of both GCS should co-ordinate safe handover offline.
-          
+
           Note that in most systems the only controlled component will be the "system manager component", and that will be the autopilot.
           However separate GCS control of a particular component is also permitted, if supported by the component.
           In this case the GCS will address MAV_CMD_REQUEST_OPERATOR_CONTROL to the specific component it wants to control.
@@ -421,7 +245,7 @@
         <param index="1" label="Sysid requesting control">System ID of GCS requesting control. 0 when command sent from GCS to autopilot (autopilot determines requesting GCS sysid from message header). Sysid of GCS requesting control when command sent by autopilot to controlling GCS.</param>
         <param index="2" label="Action">0: Release control, 1: Request control.</param>
         <param index="3" label="Allow takeover">Enable automatic granting of ownership on request (by default reject request and notify current owner). 0: Ask current owner and reject request, 1: Allow automatic takeover.</param>
-        <param index="4">Empty</param>
+        <param index="4" label="Request timeout" units="s" minValue="3" maxValue="60">Timeout in seconds before a request to a GCS to allow takeover is assumed to be rejected. This is used to display the timeout graphically on requestor and GCS in control.</param>
         <param index="5">Empty</param>
         <param index="6">Empty</param>
         <param index="7">Empty</param>
@@ -468,18 +292,6 @@
         <description>Channel data may be out of date. This is set when the receiver is unable to validate incoming data from the transmitter and has therefore resent the last valid data it received.</description>
       </entry>
     </enum>
-    <enum name="MAV_FUEL_TYPE">
-      <description>Fuel types for use in FUEL_TYPE. Fuel types specify the units for the maximum, available and consumed fuel, and for the flow rates.</description>
-      <entry value="0" name="MAV_FUEL_TYPE_UNKNOWN">
-        <description>Not specified. Fuel levels are normalized (i.e. maximum is 1, and other levels are relative to 1.</description>
-      </entry>
-      <entry value="1" name="MAV_FUEL_TYPE_LIQUID">
-        <description>A generic liquid fuel. Fuel levels are in millilitres (ml). Fuel rates are in millilitres/second.</description>
-      </entry>
-      <entry value="2" name="MAV_FUEL_TYPE_GAS">
-        <description>A gas tank. Fuel levels are in kilo-Pascal (kPa), and flow rates are in milliliters per second (ml/s).</description>
-      </entry>
-    </enum>
     <enum name="GPS_SYSTEM_ERROR_FLAGS" bitmask="true">
       <description>Flags indicating errors in a GPS receiver.</description>
       <entry value="1" name="GPS_SYSTEM_ERROR_INCOMING_CORRECTIONS">
@@ -569,16 +381,6 @@
     </enum>
   </enums>
   <messages>
-    <!-- Transactions for parameter protocol -->
-    <message id="19" name="PARAM_ACK_TRANSACTION">
-      <description>Response from a PARAM_SET message when it is used in a transaction.</description>
-      <field type="uint8_t" name="target_system">Id of system that sent PARAM_SET message.</field>
-      <field type="uint8_t" name="target_component">Id of system that sent PARAM_SET message.</field>
-      <field type="char[16]" name="param_id">Parameter id, terminated by NULL if the length is less than 16 human-readable chars and WITHOUT null termination (NULL) byte if the length is exactly 16 chars - applications have to provide 16+1 bytes storage if the ID is stored as string</field>
-      <field type="float" name="param_value">Parameter value (new value if PARAM_ACCEPTED, current value otherwise)</field>
-      <field type="uint8_t" name="param_type" enum="MAV_PARAM_TYPE">Parameter type.</field>
-      <field type="uint8_t" name="param_result" enum="PARAM_ACK">Result code.</field>
-    </message>
     <message id="295" name="AIRSPEED">
       <description>Airspeed information from a sensor.</description>
       <field type="uint8_t" name="id" instance="true">Sensor ID.</field>
@@ -587,14 +389,6 @@
       <field type="float" name="raw_press" units="hPa">Raw differential pressure. NaN for value unknown/not supplied.</field>
       <field type="uint8_t" name="flags" enum="AIRSPEED_SENSOR_FLAGS">Airspeed sensor flags.</field>
     </message>
-    <message id="298" name="WIFI_NETWORK_INFO">
-      <description>Detected WiFi network status information. This message is sent per each WiFi network detected in range with known SSID and general status parameters.</description>
-      <field type="char[32]" name="ssid">Name of Wi-Fi network (SSID).</field>
-      <field type="uint8_t" name="channel_id">WiFi network operating channel ID. Set to 0 if unknown or unidentified.</field>
-      <field type="uint8_t" name="signal_quality" units="%">WiFi network signal quality.</field>
-      <field type="uint16_t" name="data_rate" units="MiB/s">WiFi network data rate. Set to UINT16_MAX if data_rate information is not supplied.</field>
-      <field type="uint8_t" name="security" enum="WIFI_NETWORK_SECURITY">WiFi network security type.</field>
-    </message>
     <message id="354" name="SET_VELOCITY_LIMITS">
       <wip/>
       <!-- This message is work-in-progress and it can therefore change. It should NOT be used in stable production environments. -->
@@ -648,30 +442,6 @@
       <field type="uint8_t" name="percent_remaining" units="%" invalid="UINT8_MAX">Remaining battery energy. Values: [0-100], UINT8_MAX: field not provided.</field>
       <field type="uint32_t" name="status_flags" display="bitmask" enum="MAV_BATTERY_STATUS_FLAGS">Fault, health, readiness, and other status indications.</field>
     </message>
-    <message id="371" name="FUEL_STATUS">
-      <description>Fuel status.
-        This message provides "generic" fuel level information for display in a GCS and for triggering failsafes in an autopilot.
-	The fuel type and associated units for fields in this message are defined in the enum MAV_FUEL_TYPE.
-
-	The reported `consumed_fuel` and `remaining_fuel` must only be supplied if measured: they must not be inferred from the `maximum_fuel` and the other value.
-        A recipient can assume that if these fields are supplied they are accurate.
-        If not provided, the recipient can infer `remaining_fuel` from `maximum_fuel` and `consumed_fuel` on the assumption that the fuel was initially at its maximum (this is what battery monitors assume).
-	Note however that this is an assumption, and the UI should prompt the user appropriately (i.e. notify user that they should fill the tank before boot).
-
-	This kind of information may also be sent in fuel-specific messages such as BATTERY_STATUS_V2.
-	If both messages are sent for the same fuel system, the ids and corresponding information must match.
-
-	This should be streamed (nominally at 0.1 Hz).
-      </description>
-      <field type="uint8_t" name="id" instance="true">Fuel ID. Must match ID of other messages for same fuel system, such as BATTERY_STATUS_V2.</field>
-      <field type="float" name="maximum_fuel">Capacity when full. Must be provided.</field>
-      <field type="float" name="consumed_fuel" invalid="NaN">Consumed fuel (measured). This value should not be inferred: if not measured set to NaN. NaN: field not provided.</field>
-      <field type="float" name="remaining_fuel" invalid="NaN">Remaining fuel until empty (measured). The value should not be inferred: if not measured set to NaN. NaN: field not provided.</field>
-      <field type="uint8_t" name="percent_remaining" units="%" invalid="UINT8_MAX">Percentage of remaining fuel, relative to full. Values: [0-100], UINT8_MAX: field not provided.</field>
-      <field type="float" name="flow_rate" invalid="NaN">Positive value when emptying/using, and negative if filling/replacing. NaN: field not provided.</field>
-      <field type="float" name="temperature" units="K" invalid="NaN">Fuel temperature. NaN: field not provided.</field>
-      <field type="uint32_t" name="fuel_type" enum="MAV_FUEL_TYPE">Fuel type. Defines units for fuel capacity and consumption fields above.</field>
-    </message>
     <message id="414" name="GROUP_START">
       <description>Emitted during mission execution when control reaches MAV_CMD_GROUP_START.</description>
       <field type="uint32_t" name="group_id">Mission-unique group id (from MAV_CMD_GROUP_START).</field>
@@ -710,36 +480,6 @@
         Channel values are in centered 13 bit format. Range is -4096 to 4096, center is 0. Conversion to PWM is x * 5/32 + 1500.
         Channels with indexes equal or above count should be set to 0, to benefit from MAVLink's trailing-zero trimming.</field>
     </message>
-    <message id="435" name="AVAILABLE_MODES">
-      <description>Get information about a particular flight modes.
-        The message can be enumerated or requested for a particular mode using MAV_CMD_REQUEST_MESSAGE.
-        Specify 0 in param2 to request that the message is emitted for all available modes or the specific index for just one mode.
-        The modes must be available/settable for the current vehicle/frame type.
-        Each modes should only be emitted once (even if it is both standard and custom).
-      </description>
-      <field type="uint8_t" name="number_modes">The total number of available modes for the current vehicle type.</field>
-      <field type="uint8_t" name="mode_index">The current mode index within number_modes, indexed from 1.</field>
-      <field type="uint8_t" name="standard_mode" enum="MAV_STANDARD_MODE">Standard mode.</field>
-      <field type="uint32_t" name="custom_mode">A bitfield for use for autopilot-specific flags</field>
-      <field type="uint32_t" name="properties" enum="MAV_MODE_PROPERTY">Mode properties.</field>
-      <field type="char[35]" name="mode_name">Name of custom mode, with null termination character. Should be omitted for standard modes.</field>
-    </message>
-    <message id="436" name="CURRENT_MODE">
-      <description>Get the current mode.
-        This should be emitted on any mode change, and broadcast at low rate (nominally 0.5 Hz).
-        It may be requested using MAV_CMD_REQUEST_MESSAGE.
-      </description>
-      <field type="uint8_t" name="standard_mode" enum="MAV_STANDARD_MODE">Standard mode.</field>
-      <field type="uint32_t" name="custom_mode">A bitfield for use for autopilot-specific flags</field>
-      <field type="uint32_t" name="intended_custom_mode" invalid="0">The custom_mode of the mode that was last commanded by the user (for example, with MAV_CMD_DO_SET_STANDARD_MODE, MAV_CMD_DO_SET_MODE or via RC). This should usually be the same as custom_mode. It will be different if the vehicle is unable to enter the intended mode, or has left that mode due to a failsafe condition. 0 indicates the intended custom mode is unknown/not supplied</field>
-    </message>
-    <message id="437" name="AVAILABLE_MODES_MONITOR">
-      <description>A change to the sequence number indicates that the set of AVAILABLE_MODES has changed.
-        A receiver must re-request all available modes whenever the sequence number changes.
-        This is only emitted after the first change and should then be broadcast at low rate (nominally 0.3 Hz) and on change.
-      </description>
-      <field type="uint8_t" name="seq">Sequence number. The value iterates sequentially whenever AVAILABLE_MODES changes (e.g. support for a new mode is added/removed dynamically).</field>
-    </message>
     <message id="441" name="GNSS_INTEGRITY">
       <description>Information about key components of GNSS receivers, like signal authentication, interference and system errors.</description>
       <field type="uint8_t" name="id" instance="true">GNSS receiver id. Must match instance ids of other messages from same receiver.</field>
diff --git a/message_definitions/v1.0/loweheiser.xml b/message_definitions/v1.0/loweheiser.xml
new file mode 100644
index 00000000000..d899db91ebe
--- /dev/null
+++ b/message_definitions/v1.0/loweheiser.xml
@@ -0,0 +1,55 @@
+<?xml version="1.0"?>
+<mavlink>
+  <!-- Loweheiser contact info: -->
+  <!-- company URL: https://www.loweheiser.com/ -->
+  <!-- company LinkeIn: https://www.linkedin.com/company/loweheiser -->
+  <!-- email contact: info@loweheiser.com -->
+  <!-- mavlink ID range: 10150 - 10199 -->
+  <include>minimal.xml</include>
+  <enums>
+    <enum name="MAV_CMD">
+      <!-- Loweheiser specific MAV_CMD_* commands -->
+      <entry name="MAV_CMD_LOWEHEISER_SET_STATE" value="10151">
+        <description>Set Loweheiser desired states</description>
+        <param index="1">EFI Index</param>
+        <param index="2">Desired Engine/EFI State (0: Power Off, 1:Running)</param>
+        <param index="3">Desired Governor State (0:manual throttle, 1:Governed throttle)</param>
+        <param index="4">Manual throttle level, 0% - 100%</param>
+        <param index="5">Electronic Start up (0:Off, 1:On)</param>
+        <param index="6">Empty</param>
+        <param index="7">Empty</param>
+      </entry>
+    </enum>
+  </enums>
+  <messages>
+    <message id="10151" name="LOWEHEISER_GOV_EFI">
+      <description>Composite EFI and Governor data from Loweheiser equipment.  This message is created by the EFI unit based on its own data and data received from a governor attached to that EFI unit.</description>
+      <!-- Generator fields -->
+      <field type="float" name="volt_batt" units="V">Generator Battery voltage.</field>
+      <field type="float" name="curr_batt" units="A">Generator Battery current.</field>
+      <field type="float" name="curr_gen" units="A">Current being produced by generator.</field>
+      <field type="float" name="curr_rot" units="A">Load current being consumed by the UAV (sum of curr_gen and curr_batt)</field>
+      <field type="float" name="fuel_level" units="l">Generator fuel remaining in litres.</field>
+      <field type="float" name="throttle" units="%">Throttle Output.</field>
+      <field type="uint32_t" name="runtime" units="s">Seconds this generator has run since it was rebooted.</field>
+      <field type="int32_t" name="until_maintenance" units="s">Seconds until this generator requires maintenance.  A negative value indicates maintenance is past due.</field>
+      <field type="float" name="rectifier_temp" units="degC">The Temperature of the rectifier.</field>
+      <field type="float" name="generator_temp" units="degC">The temperature of the mechanical motor, fuel cell core or generator.</field>
+      <!-- EFI fields -->
+      <field type="float" name="efi_batt" units="V"> EFI Supply Voltage.</field>
+      <field type="float" name="efi_rpm" units="rpm">Motor RPM.</field>
+      <field type="float" name="efi_pw" units="ms">Injector pulse-width in miliseconds.</field>
+      <field type="float" name="efi_fuel_flow">Fuel flow rate in litres/hour.</field>
+      <field type="float" name="efi_fuel_consumed" units="l">Fuel consumed.</field>
+      <field type="float" name="efi_baro" units="kPa">Atmospheric pressure.</field>
+      <field type="float" name="efi_mat" units="degC">Manifold Air Temperature.</field>
+      <field type="float" name="efi_clt" units="degC">Cylinder Head Temperature.</field>
+      <field type="float" name="efi_tps" units="%">Throttle Position.</field>
+      <field type="float" name="efi_exhaust_gas_temperature" units="degC">Exhaust gas temperature.</field>
+      <!-- Status fields -->
+      <field type="uint8_t" name="efi_index" instance="true">EFI index.</field>
+      <field type="uint16_t" name="generator_status">Generator status.</field>
+      <field type="uint16_t" name="efi_status">EFI status.</field>
+    </message>
+  </messages>
+</mavlink>