I'm looking for something that will be able to prevent convention attendees from entering in duplicate team names

we are hosting a competitive sporting event where attendees will need to enter in team names.  We need a program that can prevent duplicate team names.  Does JotForm have this functionality? 

It is possible to limit the form submissions based on a unique field on the form. Please refer to the guide below that can help you with this.

https://www.jotform.com/help/223-How-to-set-Form-Limits-Based-on-a-Unique-Question

Please give it a try and let us know if you need any further assistance. We will be happy to help.