Some of these form fields allow users to specify their return email address, require that users fill in certain form fields, redirect users to a certain URL, or provide a form developer with access to users' environment variables, such as what web browser they were using. Field names are case sensitive, so be careful that values match the field names used in visible form fields.
Field names are case sensitive.
In addition to descriptions of these optional visible form fields, the correct form field names and examples of initial values are shown here. When form developers use this field in a form, the email message they receive containing the form results will be from this user, indicating who submitted the form information and allowing the form developer to reply to the message. The value is the initial text that appears to the user in the text box. It will be replaced with the user-supplied value when the form is submitted. In addition to descriptions of these optional hidden form fields, the correct form field names and examples of values are shown here.