Return codes:

200 Command successful
250 Command successfully submitted to an
	asynchronous registry for processing

# lookup return codes
210 Domain available
211 Domain taken
221 Domain taken (a waiting registration exists in OpenSRS)
	(for asyncronous registries only)

# rate limiting errors
300 exceeded max command rate
310 exceeded max simultaneous connections

# internal errors
400 internal server error
405 registry error

# authentication errors
410 reseller authentication error
415 registrant (end-user) authentication error

# command errors
430 invalid command
435 permission denied
	subuser permissions
437 cannot process command because there is already
    another request waiting on this domain

# quota errors
440 exceeded registration quota
445 exceeded nameserver quota
447 exceeded subuser quota

# data errors
460 missing required field
465 invalid data supplied
	domain syntax, contact info, duplicate nameservers, etc.

# request errors
480 item not found (domain, nameserver, profile, etc)
485 entity already exists (nameserver, domain, subuser, etc)
	ie, domain taken
486 entity already exists in a processing state (usually a domain registration)
	trying again in a few seconds to a minute should resolve the issue (i.e.
	show it truly taken or available)
487 domain not transferrable
