The encyclopedia contains a set of files for graphical diagram information. Each one of the .DGX files in the encyclopedia contain the information that is necessary to display a diagram to you the way it looked the last time you worked on it. So information about which symbols are on the diagram, where they are specifically placed (3rd pixel from the upper left-hand corner), what color each is, whether the scroll bars are displayed, and so on – it is all in the DGX file.

The little pictures of diagrams that are displayed in the bottom of the Browser are .WMF (metafile). A .WMF file is created for each diagram the first time the diagram is saved and is updated whenever the diagram is saved again. Those WMF files are used by System Architect/Microsoft Word to merge diagram pictures into Microsoft Word for Windows.

A .WMF or .BMP file is created automatically every time you paste or file-copy a picture-type symbol into a diagram. One .WMF or .BMP is created for each picture.