diff --git a/message_definitions/v1.0/minimal.xml b/message_definitions/v1.0/minimal.xml
index 7ef7a7832c..ad2cf873d0 100644
--- a/message_definitions/v1.0/minimal.xml
+++ b/message_definitions/v1.0/minimal.xml
@@ -128,21 +128,21 @@
         <description>Onboard companion controller</description>
       </entry>
       <entry value="19" name="MAV_TYPE_VTOL_DUOROTOR">
-        <description>Two-rotor VTOL using control surfaces in vertical operation in addition. Tailsitter.</description>
+        <description>Two-rotor Tailsitter VTOL that additionally uses control surfaces in vertical operation. Note: should be named MAV_TYPE_VTOL_TAILSITTER_DUOROTOR.</description>
       </entry>
       <entry value="20" name="MAV_TYPE_VTOL_QUADROTOR">
-        <description>Quad-rotor VTOL using a V-shaped quad config in vertical operation. Tailsitter.</description>
+        <description>Quad-rotor Tailsitter VTOL using a V-shaped quad config in vertical operation. Note: should be named MAV_TYPE_VTOL_TAILSITTER_QUADROTOR.</description>
       </entry>
       <entry value="21" name="MAV_TYPE_VTOL_TILTROTOR">
-        <description>Tiltrotor VTOL</description>
+        <description>Tiltrotor VTOL. Fuselage and wings stay (nominally) horizontal in all flight phases. It able to tilt (some) rotors to provide thrust in cruise flight.</description>
       </entry>
-      <!-- Entries up to 25 reserved for other VTOL airframes -->
-      <entry value="22" name="MAV_TYPE_VTOL_RESERVED2">
-        <description>VTOL reserved 2</description>
+      <entry value="22" name="MAV_TYPE_VTOL_FIXEDROTOR">
+        <description>VTOL with separate fixed rotors for hover and cruise flight. Fuselage and wings stay (nominally) horizontal in all flight phases.</description>
       </entry>
-      <entry value="23" name="MAV_TYPE_VTOL_RESERVED3">
-        <description>VTOL reserved 3</description>
+      <entry value="23" name="MAV_TYPE_VTOL_TAILSITTER">
+        <description>Tailsitter VTOL. Fuselage and wings orientation changes depending on flight phase: vertical for hover, horizontal for cruise. Use more specific VTOL MAV_TYPE_VTOL_DUOROTOR or MAV_TYPE_VTOL_QUADROTOR if appropriate.</description>
       </entry>
+      <!-- Entries 24/25 reserved for other VTOL airframe -->
       <entry value="24" name="MAV_TYPE_VTOL_RESERVED4">
         <description>VTOL reserved 4</description>
       </entry>