Reference.md in ruby-dbus-0.18.0.beta1

- old
+ new

@@ -151,11 +151,11 @@
 #### Names
 #### Types and Values, D-Bus -> Ruby
 
 D-Bus booleans, numbers, strings, arrays and dictionaries become their straightforward Ruby counterparts.
 
-Structs become arrays.
+Structs become frozen arrays.
 
 Object paths become strings.
 
 Variants are simply unpacked to become their contained type.
 (ISSUE: prevents proper round-tripping!)
@@ -188,14 +188,21 @@
 3. **Deprecated:** A pair [String, value], where String is a valid
    signature of a single complete type, marshalls value as that
    type. This will hit you when you rely on method (2) but happen to have
    a particular string value in an array.
 
+##### Structs
+
+If a **STRUCT** `(...)` is expected you may pass
+
+- an [Array](https://ruby-doc.org/core/Array.html) (frozen is fine)
+- a [Struct](https://ruby-doc.org/core/Struct.html)
+
 ##### Byte Arrays
 
 If a byte array (`ay`) is expected you can pass a String too.
 The bytes sent are according to the string's
-[encoding](http://ruby-doc.org/core-2.0.0/Encoding.html).
+[encoding](http://ruby-doc.org/core/Encoding.html).
 
 ##### nil
 
 `nil` is not allowed by D-Bus and attempting to send it raises an exception
 (but see [I#16](https://github.com/mvidner/ruby-dbus/issues/16)).