diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/TwinCATDriverFactoryExtensions.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/TwinCATDriverFactoryExtensions.cs
index 72430816..68dbe38b 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/TwinCATDriverFactoryExtensions.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/TwinCATDriverFactoryExtensions.cs
@@ -89,8 +89,9 @@ public static class TwinCATDriverFactoryExtensions
         // Driver.TwinCAT-003: Structure-typed pre-declared tags are not supported. The driver's
         // atomic surface cannot read/write UDT blobs — MapToClrType falls through to typeof(int)
         // and ConvertForWrite throws NotSupportedException, producing garbage reads or late
-        // runtime failures. BrowseSymbolsAsync already correctly yields DataType = null for
-        // Structure symbols so they never appear in the discovered address space. Reject here
+        // runtime failures. BrowseSymbolsAsync expands a Structure/UDT/FB symbol into its atomic
+        // member leaves (the container itself is never surfaced as a writable Structure node), so the
+        // supported way to address members is discovery — not a pre-declared Structure tag. Reject here
         // with a clear error so operators get a configuration-time failure, not a silent wrong value.
         if (dataType == TwinCATDataType.Structure)
             throw new InvalidOperationException(