1. A product comprising: a computer-readable memory; graphical user interface (GUI) type model logic stored on the computer-readable memory and executable by a processor, the GUI type model logic is responsive to selection of a reference GUI type model to use to create a GUI element type mapping; builder logic stored on the computer-readable memory and executable by the processor, the builder logic comprising: association logic that when executed by the processor creates the GUI element type mapping that links a GUI element type to a GUI element in a GUI; message creation logic that when executed by the processor builds a GUI element type specification message that signifies that data within the message specifies a type mapping for a GUI element; and communication logic that when executed by the processor causes the processor to communicate the GUI element type specification message with the type mapping for the GUI element to a downstream processing system.