Variables can be used in most text properties for Actions. To use a Variable in a property, enclose the variable in percent symbols,

eg. : %OUTPUTDIR%

If you need to use a % symbol in a property, make sure you escape it with another %, eg. %%. See Escaping Variable Contents.

A common use for variables is to set file paths, for example to set the File Spec for Set File Attributes:

Variables can also be used in Script Events.

See also: Variable Sense.