HTML Form Builder

I only have one question: - what do I have to enter as "Validation Format" for an email field? second, I made an extension in "controller/main.py":; #default values ... else: if df.default_value == "user_id": secure_values[df.field_id.name] = request.env.user.id elif df.default_value == "partner_id": secure_values[df.field_id.name] = request.env.user.partner_id.id # Added by ECFSolutions to store the metadata that is submitted with a form when sending. # Odoo takes over these metadata at the moment of form submission, but does not save them and loses them in the further course of the process. # This storage is triggered by entering the default value "metadata" in the field where the metadata should be stored. elif df.default_value == "metadata": environ = request.httprequest.headers.environ meta = "IP = "+ str(environ.get("REMOTE_ADDR")) + "\r\n" \ + "USER_AGENT = "+ str(environ.get("HTTP_USER_AGENT")) + "\r\n" \ + "ACCEPT_LANGUAGE = " + str(environ.get("HTTP_ACCEPT_LANGUAGE")) + "\r\n" \ + "REFERER = " + str(environ.get("HTTP_REFERER")) secure_values[df.field_id.name] = meta # End of the change by ECFSolutions else: ... Thanks in any case. Best regards Christian