The Attendees exports contain all the information the Registrant gave when signing up for the event. This always includes Name, Email, Company, and Title. Sometimes it includes additional information, such as phone number, address, city, state, zip code, etc. 

If you’d like to collect specific information from your registrants (such as T-shirt Size or Guest Name, for example), please let your event manager know and they can create a special registration field for you.