How to Prevent Duplicate Event Registrations in Dynamics 365 Customer Insights (with Form Submission Validation)s
Some months ago, I got the question if there was a way to limit the Registrations for an event to one Registration per person in Dynamics 365 Customer Insights Journeys. I thought then, that there is no setting for this, so I decided to investigate, and after some research I stumbled into this documentation of Microsoft: Customize form submission validation
Then I thought that if there is a way of validating a form before the submission, we could avoid it altogether.