Question identifiers offer you a way to give each question type a shorter name that can be displayed when you export the data into Excel and Analytics software. Shorter identifiers also make the process of building complex skipping patterns a lot easier.
How to Use:
In the options section of every question, there is a text box that you can use to supply an identifier. Identifiers are not mandatory but are recommended, especially for more complex surveys.
Watch this video tutorial on creating an online survey:
More information on question identifiers here.