Special Fields

Special fields start with _ and control form behavior. They are not stored in submission data.

`_next` - Redirect URL

Redirect users after successful submission:

<input type="hidden" name="_next" value="https://yoursite.com/thanks">

This overrides the redirect URL set in form settings.

`_subject` - Email Subject

Customize the notification email subject:

<input type="hidden" name="_subject" value="New inquiry from website">

With Variables

Include form data in the subject:

<input type="hidden" name="_subject" value="Contact from {{ name }}">

`_replyto` - Reply-To Address

Set the Reply-To header for notification emails:

<input type="hidden" name="_replyto" value="user@example.com">

Or use a form field:

<input type="email" name="_replyto" placeholder="Your email" required>

If you have a field named email, it’s automatically used as Reply-To. Use _replyto to override this.

`_gotcha` - Honeypot

Built-in honeypot field for spam protection:

<input type="text" name="_gotcha" style="display:none" tabindex="-1" autocomplete="off">

If this field has a value, the submission is marked as spam.

`_cc` - Carbon Copy

Send a copy of the notification to additional emails:

<input type="hidden" name="_cc" value="manager@company.com,team@company.com">

Example: Complete Form

<form action="https://api.formbnb.com/f/YOUR_ORG/YOUR_FORM" method="POST">
  <!-- Special fields -->
  <input type="hidden" name="_next" value="https://yoursite.com/thanks">
  <input type="hidden" name="_subject" value="New contact from {{ name }}">
  <input type="text" name="_gotcha" style="display:none" tabindex="-1">
  
  <!-- Regular fields -->
  <input type="text" name="name" placeholder="Name" required>
  <input type="email" name="email" placeholder="Email" required>
  <textarea name="message" placeholder="Message" required></textarea>
  
  <button type="submit">Send</button>
</form>

Field Reference

Field	Type	Description
`_next`	URL	Redirect URL after submission
`_subject`	String	Email subject (supports `{{ variables }}`)
`_replyto`	Email	Reply-To address for notifications
`_gotcha`	String	Honeypot field (should be empty)
`_cc`	Emails	Additional notification recipients
`_optin`	Boolean	Marketing opt-in flag

Notes

Special fields are not stored in submission data
They only affect form behavior
Field names are case-sensitive
You can use hidden inputs or regular inputs

Get Started

Features

Integrations

Libraries

`_next` - Redirect URL

`_subject` - Email Subject

With Variables

`_replyto` - Reply-To Address

`_gotcha` - Honeypot

`_cc` - Carbon Copy

Example: Complete Form

Field Reference

Notes

​_next - Redirect URL

​_subject - Email Subject

​With Variables

​_replyto - Reply-To Address

​_gotcha - Honeypot

​_cc - Carbon Copy

​Example: Complete Form

​Field Reference

​Notes

`_next` - Redirect URL

`_subject` - Email Subject

With Variables

`_replyto` - Reply-To Address

`_gotcha` - Honeypot

`_cc` - Carbon Copy

Example: Complete Form

Field Reference

Notes