When you are uploading a participant spreadsheet in a new event, notice at the bottom of the field mapping, there is an options which says "Extend imported data from matching delegates".
Select that and then you will be prompted to select which fields you would like to auto-complete. By holding down the "Control" key you can select multiple fields. After making your selection, please click "save".
The system will then scan other events and auto-complete matching participants data. A match will be made when the participant's first name, last name and email address are identical. The system will also pull the most recent registration data.
If you add a single participant manually, you can auto-complete this participant's data by clicking on the "autocomplete" button on the individual's listing, as illustrated below. Click here for instructions on how to navigate to a participant's registration listing.