diff --git a/src/TODO.txt b/src/TODO.txt
index 2826022..6cc6ae7 100644
--- a/src/TODO.txt
+++ b/src/TODO.txt
@@ -104,6 +104,7 @@
 * Testbench did not catch Bug, where the Pub ACKNACK was sent to as Sub ACKNACK (ACKNACK Destinations were flipped). Extend testbench to catch this case.
 * Testbench did not catch rtps_writer not sending HEARTBEATS if PUSH_MODE=FALSE & DURABILITY=TRANSIENT_LOCAL
 * DATA sent before first HEARTBEAT: https://github.com/ros2/rmw_cyclonedds/issues/367
+* If VHDL-2019 is used, we can use "conditional analysis statements" to see if we are in a simulation (see https://insights.sigasi.com/tech/what-is-new-in-vhdl-2019-part4/)
 
 * Fast-RTPS does not follow DDSI-RTPS Specification
     - Open Github Issue
diff --git a/src/ros2/unique_identifier_msgs/UUID.idl b/src/ros2/unique_identifier_msgs/UUID.idl
new file mode 100644
index 0000000..dac3b5e
--- /dev/null
+++ b/src/ros2/unique_identifier_msgs/UUID.idl
@@ -0,0 +1,18 @@
+// generated from rosidl_adapter/resource/msg.idl.em
+// with input from unique_identifier_msgs/msg/UUID.msg
+// generated code does not contain a copyright notice
+
+
+module unique_identifier_msgs {
+  module msg {
+    typedef uint8 uint8__16[16];
+    @verbatim (language="comment", text=
+      " A universally unique identifier (UUID)." "\n"
+      "" "\n"
+      "  http://en.wikipedia.org/wiki/Universally_unique_identifier" "\n"
+      "  http://tools.ietf.org/html/rfc4122.html")
+    struct UUID {
+      uint8__16 uuid;
+    };
+  };
+};
diff --git a/src/ros2/unique_identifier_msgs/UUID.msg b/src/ros2/unique_identifier_msgs/UUID.msg
new file mode 100644
index 0000000..c77b6a7
--- /dev/null
+++ b/src/ros2/unique_identifier_msgs/UUID.msg
@@ -0,0 +1,6 @@
+# A universally unique identifier (UUID).
+#
+#  http://en.wikipedia.org/wiki/Universally_unique_identifier
+#  http://tools.ietf.org/html/rfc4122.html
+
+uint8[16] uuid