-* <s> : String
-* <ay> : Byte Array
-* <aay> : Array of Byte Arrays
-* <as> : String Array
-* <ax> : Array of signed 64 bit integer
-* <b> : Boolean (0|1)
-* <x> : Signed 64 bit integer
+* <a> : Array of ... (comma-separated list)
+* (...) : Struct (cannot be sent via `dbus-send`)
+* <b> : Boolean (false|true) (boolean:)
+* <i> : Signed 32-bit (int) integer (int32:)
+* <o> : DBusPath object (objpath:)
+* <s> : String (string:)
+* <x> : Signed 64-bit (long) integer (int64:)
+* <y> : Unsigned 8-bit (byte) integer (byte:)