### Username for external authentication

When a user is authenticated by some service external to the site, this field contains the identifier for the user on the remote service. It is possible for a user to have several remote usernames stored in Mahara, but each one must be associated with a different external authentication method.

The current rules for the update of this field are as follows:

- If you wipe the contents of this field and submit your changes, the external username associated with the selected authentication method will be reset to the default username.
- If you update the contents of this field, the external username will be reset for this authentication method, or a new one will be created if it doesn't exist yet.