In the user profile module if we need to add a description for one of the fields all we have to do is edit the field in the admin and add a description to it which is then displayed below the head of the field during registration.

This can be done for all fields accept username, password and email as these are not mentioned in the fields section of the module.

I need to add some description to the username field. Where can i add it so its visible in the registration form like description for any other field.

Kindly help...