The .data property stores information within ActionScript variable types, known as attributes or slots. You cannot write a value directly to the .data property, but you can create collections of attributes. Each attribute could be an object, array, or any type of ActionScript variable. When values are changed within the attribute (or slot), Flash Communication Server announces the change to every connected client sending the name of the changed attribute to the client. This announcement is handled by the ActionScript onSync event.