The basic macro format versus the advanced macro format

You must choose the format that you want your macro to be stored in: either the basic macro format or the advanced macro format.

The basic macro format is the default format. It supports a basic level of function but it does not include support for expression evaluation, variables, or some other features supported by the advanced macro format. Nevertheless, you should choose the basic macro format initially unless you already know that you are going to use expressions and variables. You can easily switch your macro to the advanced macro format later on. (In contrast, if you start out with the advanced macro format it is much more difficult to switch your macro to the basic macro format.)

You indicate which format you want with the Use Variables and Arithmetic Expressions in Macro checkbox on the Macro tab of the Macro Editor:
The basic macro format:
In contrast the advanced macro format: