diff --git a/Tools/autotest/param_metadata/xmlemit.py b/Tools/autotest/param_metadata/xmlemit.py
old mode 100644
new mode 100755
index ddff3d4232a88..5cf0780e44f55
--- a/Tools/autotest/param_metadata/xmlemit.py
+++ b/Tools/autotest/param_metadata/xmlemit.py
@@ -69,9 +69,12 @@ def sorted_Values_keys(self, nv_pairs, zero_at_top=False):
         keys = nv_pairs.keys()
         def sort_key(value):
             description = nv_pairs[value]
-            if zero_at_top and value == "0":
-                # make sure this item goes at the top of the list:
-                return "AAAAAAA"
+            if zero_at_top:
+                # make sure -1 and 0 appear at the top of the list
+                if value == "-1":
+                    return "0000000"
+                if value == "0":
+                    return "0000001"
             return description
         return sorted(keys, key=sort_key)
 
diff --git a/libraries/AP_CANManager/AP_CANManager_CANDriver_Params.cpp b/libraries/AP_CANManager/AP_CANManager_CANDriver_Params.cpp
index 21279fd5aea21..447a0cc178403 100644
--- a/libraries/AP_CANManager/AP_CANManager_CANDriver_Params.cpp
+++ b/libraries/AP_CANManager/AP_CANManager_CANDriver_Params.cpp
@@ -27,6 +27,7 @@ const AP_Param::GroupInfo AP_CANManager::CANDriver_Params::var_info[] = {
     // @Param: PROTOCOL
     // @DisplayName: Enable use of specific protocol over virtual driver
     // @Description: Enabling this option starts selected protocol that will use this virtual driver
+    // @SortValues: AlphabeticalZeroAtTop
     // @Values: 0:Disabled,1:DroneCAN,4:PiccoloCAN,6:EFI_NWPMU,7:USD1,8:KDECAN,10:Scripting,11:Benewake,12:Scripting2,13:TOFSenseP,14:NanoRadar
     // @User: Advanced
     // @RebootRequired: True
@@ -51,6 +52,7 @@ const AP_Param::GroupInfo AP_CANManager::CANDriver_Params::var_info[] = {
     // @Param: PROTOCOL2
     // @DisplayName: Secondary protocol with 11 bit CAN addressing
     // @Description: Secondary protocol with 11 bit CAN addressing
+    // @SortValues: AlphabeticalZeroAtTop
     // @Values: 0:Disabled,7:USD1,10:Scripting,11:Benewake,12:Scripting2,13:TOFSenseP,14:NanoRadar
     // @User: Advanced
     // @RebootRequired: True
diff --git a/libraries/AP_Mount/AP_Mount_Params.cpp b/libraries/AP_Mount/AP_Mount_Params.cpp
index 13db92c4e0c19..27be1662c4869 100644
--- a/libraries/AP_Mount/AP_Mount_Params.cpp
+++ b/libraries/AP_Mount/AP_Mount_Params.cpp
@@ -9,6 +9,7 @@ const AP_Param::GroupInfo AP_Mount_Params::var_info[] = {
     // @Param: _TYPE
     // @DisplayName: Mount Type
     // @Description: Mount Type
+    // @SortValues: AlphabeticalZeroAtTop
     // @Values: 0:None, 1:Servo, 2:3DR Solo, 3:Alexmos Serial, 4:SToRM32 MAVLink, 5:SToRM32 Serial, 6:Gremsy, 7:BrushlessPWM, 8:Siyi, 9:Scripting, 10:Xacti, 11:Viewpro, 12:Topotek, 13:CADDX
     // @RebootRequired: True
     // @User: Standard
diff --git a/libraries/AP_OpticalFlow/AP_OpticalFlow.cpp b/libraries/AP_OpticalFlow/AP_OpticalFlow.cpp
index 2b86e63f73d4f..2927eb4d3255e 100644
--- a/libraries/AP_OpticalFlow/AP_OpticalFlow.cpp
+++ b/libraries/AP_OpticalFlow/AP_OpticalFlow.cpp
@@ -26,6 +26,7 @@ const AP_Param::GroupInfo AP_OpticalFlow::var_info[] = {
     // @Param: _TYPE
     // @DisplayName: Optical flow sensor type
     // @Description: Optical flow sensor type
+    // @SortValues: AlphabeticalZeroAtTop
     // @Values: 0:None, 1:PX4Flow, 2:Pixart, 3:Bebop, 4:CXOF, 5:MAVLink, 6:DroneCAN, 7:MSP, 8:UPFLOW
     // @User: Standard
     // @RebootRequired: True
diff --git a/libraries/AP_Proximity/AP_Proximity_Params.cpp b/libraries/AP_Proximity/AP_Proximity_Params.cpp
index ad85936067fe4..ffee3e4c21f86 100644
--- a/libraries/AP_Proximity/AP_Proximity_Params.cpp
+++ b/libraries/AP_Proximity/AP_Proximity_Params.cpp
@@ -8,6 +8,7 @@ const AP_Param::GroupInfo AP_Proximity_Params::var_info[] = {
     // @Param: _TYPE
     // @DisplayName: Proximity type
     // @Description: What type of proximity sensor is connected
+    // @SortValues: AlphabeticalZeroAtTop
     // @Values: 0:None,7:LightwareSF40c,2:MAVLink,3:TeraRangerTower,4:RangeFinder,5:RPLidarA2,6:TeraRangerTowerEvo,8:LightwareSF45B,10:SITL,12:AirSimSITL,13:CygbotD1, 14:DroneCAN, 15:Scripting, 16:LD06, 17: MR72_CAN
     // @RebootRequired: True
     // @User: Standard
diff --git a/libraries/AP_SerialManager/AP_SerialManager.cpp b/libraries/AP_SerialManager/AP_SerialManager.cpp
index 4fe78f3ab8610..3402e1b13d327 100644
--- a/libraries/AP_SerialManager/AP_SerialManager.cpp
+++ b/libraries/AP_SerialManager/AP_SerialManager.cpp
@@ -183,6 +183,7 @@ const AP_Param::GroupInfo AP_SerialManager::var_info[] = {
     // @Param: 1_PROTOCOL
     // @DisplayName: Telem1 protocol selection
     // @Description: Control what protocol to use on the Telem1 port. Note that the Frsky options require external converter hardware. See the wiki for details.
+    // @SortValues: AlphabeticalZeroAtTop
     // @Values: -1:None, 1:MAVLink1, 2:MAVLink2, 3:Frsky D, 4:Frsky SPort, 5:GPS, 7:Alexmos Gimbal Serial, 8:Gimbal, 9:Rangefinder, 10:FrSky SPort Passthrough (OpenTX), 11:Lidar360, 13:Beacon, 14:Volz servo out, 15:SBus servo out, 16:ESC Telemetry, 17:Devo Telemetry, 18:OpticalFlow, 19:RobotisServo, 20:NMEA Output, 21:WindVane, 22:SLCAN, 23:RCIN, 24:EFI Serial, 25:LTM, 26:RunCam, 27:HottTelem, 28:Scripting, 29:Crossfire VTX, 30:Generator, 31:Winch, 32:MSP, 33:DJI FPV, 34:AirSpeed, 35:ADSB, 36:AHRS, 37:SmartAudio, 38:FETtecOneWire, 39:Torqeedo, 40:AIS, 41:CoDevESC, 42:DisplayPort, 43:MAVLink High Latency, 44:IRC Tramp, 45:DDS XRCE, 46:IMUDATA, 48:PPP
     // @User: Standard
     // @RebootRequired: True