Go to settings --> forms --> click edit form fields beside a form --> click on the field to edit it
Label - Field title
Mandatory - forms are marked complete when all mandatory fields on the form are filled out
Field description - light gray text that appears beneath the field label
Placeholder - This will show in the input field and is used as a way to guide the user what type of information should be entered. The text will disappear only when the user starts entering text. For example in a field asking for first name you can add a placeholder of "John".
Field hidden from users - the field will only show to admins on the back end
Add field to filter options on backend - use this for discount codes
Maximum characters allowed - Enter a number if you want to limit the number of characters that can be entered. A good use for this ability is for zip codes for example.
Minimum characters allowed - Enter a number if you want to force the user a minimum number of characters. A good use for this are fields for for information with set values such as social security numbers, id codes, coupon codes etc...
Maximum words allowed - Enter a number if you want to limit the number of words that can be entered. Note that if you also set the "Maximum characters allowed" it will take precedence. This means that once the number of characters is met the user will no be able to enter extra characters.
Extra Data Checks
Password - Will force the user to enter at least 6 digits and will allow letters, numbers only and special characters (no spaces for example)
Email - Will force the user to enter a valid email. This is a limited check that will confirm only the structure. It will also not allow you to select the field later as an email field when you want to send out emails or communicate with users. If you wish to have a more extensive email data check select the email field type that includes this check as well.
Phone - Will make sure the user entered a valid phone number. This is a limited check so if you need to validate phone numbers it is advised to use the phone number field.
Phone with 10 digits - Same as phone but will also force the user to enter a phone with 10 digits in it. It will disregard any character that is not a number when counting.
Number - Will confirm the user is entering only numbers and no other type of characters. Use the number field if you want to also be able to filter according to number ranges and additional features.
Latin Characters - Will confirm the user is only entering latin characters. This does not include any special characters that are in French (for example) or any characters from non-latin languages.
URL - Will confirm the information entered has a URL structure. Use this when you need users to enter their website or other links to confirm they are accurate and will work.
Routing Number - Will confirm the value has the structure of a US routing number. It will also test against routing number databases to confirm the value entered can exist.