> 
> Has the registrar said why they can't help? It seems to me logical
> that the registrar provides a domain availability service as they are
> your interface to the registry.
> 

There are really two issues here:

(1) Domain Availability check
- a registrar does this via an EPP check command to the registry
- Melbourne IT does provide access to this via its API to its authorised
resellers
- resellers should contact their registrar regarding this functionality

(2) WHOIS service
- companies often like to have a WHOIS service running on their website as a
service to their customers (see for example http://whois.melbourneit.com.au)
- note this returns less information than it used to with AUNIC:
Registrant
Registrant contact name
Registrant email address
Tech contact name
Tech email address
Nameserver information
- auDA in an attempt to limit abuse of the WHOIS has imposed limits on the
number of WHOIS queries that a single user can perform on the WHOIS

Issues with WHOIS limits:
- you could require all end users to always query the AusRegistry WHOIS
directly
(http://www.ausregistry.com.au/domains/search.php) in which case you can
centrally manage individual WHOIS query rates.  Resellers could simple
provide a link to the AusRegistry WHOIS service.
- you could allow orgs such as registrars and resellers to have access to
AusRegistry WHOIS will larger limits on query rates - the problem with this
is that this opens backdoors for single users to hide systematic mining of
WHOIS data behind a reseller or registrar interface

A possible solution would be to allow an organisation (accredited registrar
or authorised reseller of registrar) to have large WHOIS limits so they can
offer WHOIS services to their customers - PROVIDED that certify that they
themselves implement filtering on WHOIS limits by end users of their
websites.

Melbourne IT presently does not allow direct reseller access to a WHOIS
command for ".au" because of the issues above (ie if we open up WHOIS
indiscriminately we are providing a backdoor interface to AusREgistry WHOIS
that defeats the WHOIS limits).

This whole matter needs to be considered further by auDA, AusRegistry, and
accredited registrars.

Regards,
Bruce Tonkin