email_unique
Check if an entered e-mail address is unique, by looking in the m_identity table for the email key:
<input type="text" id="email" name="email" value="" />
{% validate id="email" type={email} type={email_unique} %}
Optionally, an rsc_id parameter can be given to the validator to skip that particular id when doing the uniqueness check. This is useful when you are displaying a form in which the user is editing his own email address.