A custom URL variable / GET parameter is a way to send your own data to the survey. You can transfer data such as Order ID, Customer ID, Country, Language, Gender, Name or whatever you need.
1. Click on the Settings in the main menu in your survey editor and go to Advanced settings in the left-hand menu.
2. Turn the Custom URL parameters ON, and type in the names of the parameters you'd like to connect. Unless you know what you're doing, it's recommended that you get help from a friend or colleague who can help you with setting it up properly to ensure that all the data you need is collected.
3. Your created parameters will be added as new columns in your XLS file containing individual answers.