You can configure a graphics object so that if the variable tag specified for the object is not defined in the tag database at compile time, the object does not display on a graphics page.
The expression entered in the Hidden Whenfield of an object's property is used to determine if the object will display. The expression evaluates to either TRUE or FALSE and the object is hidden when the expression is TRUE.
You define the variable tag and conditions under which the object is hidden by entering an IFDEF statement into the Hidden When field when you configure the object. The IFDEF statement is evaluated by the compiler and the value of the resulting expression or variable tag will determine whether or not the object is hidden.
This can significantly reduce the number of necessary genies, as the configuration engineer does not need to generate several smaller genies to cater to operations driven by a slightly different range of tags.
See IFDEF macro for more information on using the IFDEF macro for hiding graphics objects. For more information on the IFDEF macro in general, see IFDEF.