JViews Diagrammer introduces the concept of symbol used to populate the graphical interfaces.

A symbol is an abstraction of composite graphic that can be used through style sheets or directly through Java™ code. Symbols are organized within palettes, and they have a dedicated tool to edit them (the Symbol Editor). By default, such symbols are based on a set of CSS directives which can be interpreted at run time. As a consequence, palettes of symbols can be edited and modified at any time to improve symbols or to add new symbols to the application. The other way to use symbols is to generate the Java source code corresponding to each symbol. In this case, symbols are tightly integrated with the application and cannot be modified from the outside.

A composite graphic object is an instance of IlvSDMCompositeNode. This class is in the SDM package but it is a subclass of IlvCompositeGraphic which is a JViews Framework class.