Shape data, or custom properties, as it used to be called, is the key to visualising information with Microsoft Visio. If you want to see the information stored in a shape, or to use the built-in reporting, then you need to become familiar with shape data. If you want to have hidden information or to build in formulae that change shape data or parts of the graphics, then use User-defined cells. You can even use the right mouse menu to change shape data values by using the Action cells.

At times, you need to be able to edit shape data but, at other times, you need only to view it, or you may even want to make selected shape data invisible. You may want to have drop-down lists to select from, with the content of the list changed, depending on the value selected in another list. You can change the color of all or parts of a shape, or even change the appearance of a shape, in response to the value in a shape data row.

Customizing Visio shapes to suit your requirements reduces the time needed to create data diagrams, provides you with your corporate look and feel, and increases the insight of your audience.

Some tools within Microsoft Visio can create shape data automatically, so you need to understand what they are doing, so you can use them to your best advantage. Some sections in the ShapeSheet are always there because they are required for every shape but, others, such as Shape Data, User-defined cells, or Actions are only created when they are required. Every cell can be identified by name or its Section Row Column (SRC) value.