This is a built-in template used for filling the catch parameter when it is generated, e.g. when using the Code | Surround with... function.
The template is editable, e.g. you can make the generated parameter final and always use predefined name despite of qualified name of the caught exception.
Predefined variables will take the following values:
${EXCEPTION}   name of the Exception variable specified as a catch parameter derived from caught exception type, e, if qualified name ends with Exception
${EXCEPTION_TYPE}   type of the catch parameter