Validation utilities

To ease the process of validating user registration data, django-registration includes some validation-related data and utilities in registration.validators.

The available error messages are:


Error message raised by RegistrationFormUniqueEmail when the supplied email address is not unique.


Error message raised by RegistrationFormNoFreeEmail when the supplied email address is rejected by its list of free-email domains.


Error message raised by ReservedNameValidator when it is given a value that is a reserved name.


Error message raised by RegistrationFormTermsOfService when the terms-of-service field is not checked.

All of these error messages are marked for translation; most have translations into multiple languages already in django-registration.

Additionally, one custom validator is provided:

class registration.validators.ReservedNameValidator

A custom validator (see Django’s validators documentation) which prohibits the use of a reserved name as the value.

By default, this validator is applied to the username field of registration.forms.RegistrationForm and all of its subclasses. The validator is applied in a form-level clean() method on RegistrationForm, so to remove it (not recommended), simply subclass RegistrationForm and override clean(). For no custom form-level validation, you could simply implement it as:

def clean(self):

If you want to supply your own custom list of reserved names, you can subclass RegistrationForm and set the attribute reserved_names to the list of values you want to disallow.


Why reserved names are reserved

Many Web applications enable per-user URLs (to display account information), and some may also create email addresses or even subdomains, based on a user’s username. While this is often useful, it also represents a risk: a user might register a name which conflicts with an important URL, email address or subdomain, and this might give that user control over it.

django-registration includes a list of reserved names, and rejects them as usernames by default, in order to avoid this issue.

The default list of reserved names, if you don’t specify one, is DEFAULT_RESERVED_NAMES. The validator will also reject any value beginning with the string ".well-known" (see RFC 5785).

Several constants are provided which are used by this validator:


A list of hostnames with reserved or special meaning (such as “autoconfig”, used by some email clients to automatically discover configuration data for a domain).


A list of protocol-specific hostnames sites commonly want to reserve, such as “www” and “mail”.


A list of email usernames commonly used by certificate authorities when verifying identity.


A list of common email usernames specified by RFC 2142.


A list of common email usernames used for automated messages from a Web site (such as “noreply” and “mailer-daemon”).


A list of common filenames with important meanings, such that usernames should not be allowed to conflict with them (such as “favicon.ico” and “robots.txt”).


Other names, not covered by the above lists, which have the potential to conflict with common URLs or subdomains, such as “blog” and “docs”.


A list made of the concatentation of all of the above lists, used as the default set of reserved names for ReservedNameValidator.