diff --git a/msg/RobotTrajectory.msg b/msg/RobotTrajectory.msg
index 94e883a..955d915 100644
--- a/msg/RobotTrajectory.msg
+++ b/msg/RobotTrajectory.msg
@@ -1,2 +1,4 @@
 trajectory_msgs/JointTrajectory joint_trajectory
 trajectory_msgs/MultiDOFJointTrajectory multi_dof_joint_trajectory
+# The name of the planning group (= group of joints) which this trajectory actuates
+string group_name