The mainstream brokers have stricter controls in place based on my experience Ferretous.
Etrade, NAB and Comsec have filters in place and if your order does not fall within a set criteria, your order will be sent to a trading operator who will either accept or reject your order. This can be time consuming and has ruined many a trade of mine in the past.
The mainstream brokers have more retail clients, so i suppose they could argue that they need stricter filters in place to stop any wayward orders from people they presume don't know what they're doing.
All brokers would fall under general ASX guidelines though, some are more lenient than others.
