How can you ensure that a custom field is not displayed on the form and its value cannot be changed?

The choice to change the Default Access level to None is effective in ensuring that a custom field is not displayed on the form and that its value cannot be altered. When the access level for a field is set to None, it is as if the field does not exist for users based on their assigned roles. As a result, the field remains completely hidden from the user interface, ensuring that users cannot see or modify the field's value. This setting is a definitive way to restrict any interaction with the field across all roles.

In contrast, other options may not fully achieve the desired outcome. Hiding the field in the script settings may only make it invisible during specific transactions or under certain conditions; it might still be accessible in other contexts. Setting the field as read-only prevents users from modifying its value but does not necessarily hide it from the form. Lastly, removing the field from all roles does not by itself prevent the data from being editable; it merely restricts visibility without explicitly disabling the ability to modify the value under other roles. These nuances emphasize the precision of setting the Default Access level to None as the most reliable method for ensuring complete concealment and protection of a custom field's value.