Custom Variables are special variables used to store additional information which can be passed to the survey. The additional info passed via the variables are stored with the respondents response collected. Variable mapping helps dramatically when you have a lot of variables used in your survey. It helps to work with your own codes instead of using a system syntax (custom1, custom2, etc.,). You can use variable mapping to assign appropriate names to the variables which also appears as the column headers in the reports downloaded.
To add variable mapping go to:
This feature is available with the following license :