How can I identify people who have already been surveyed?

Hello. I need the interviewed to have a voucher, or some code, to indicate that he has already been surveyed. Is it possible to do so?

Hi @Marcelo_Raul_SCARONE! If you were doing this survey on paper, how would you know that this person had already been surveyed?

Also, when you get a chance, please introduce yourself here. I'd also encourage you to add a real picture as your avatar. It helps build community :slight_smile: