The ability to accept only specific email domains in an email field. For example, if I work for Acme Inc. and make a form for my employees, I want to require that the email field have @acme.com in it. This will avoid employees submitting requests from their personal email address by accident or someone from outside the company submitting requests. Logistically, this could be as simple as an option that can be enabled when adding the field. When enabled the user can enter a list of domains that are acceptable (would be important to allow more than just one domain).
Edit: there is a hacky way to do this with conditionals by showing text warnings / hiding fields but it leads to very quirky user experience and people submitting empty requests
