If you are collecting sensitive information from your customers, there are multiple ways to reduce your exposure of leaking that information in the Schema tab of a variant.
Variables with this checked will be excluded from any payloads sent to third-party integrations in the Integrations tab.
Variables with this checked will be excluded from any payloads sent to Formsort. If you have a webhook configured, they will be sent to that webhook URL directly from the user's browser, meaning that formsort does not receive nor handle this data.
Note that with this enabled, if a user returns to an already-started flow, they will have to re-enter their sensitive information since it will not be retrievable from Formsort.