`  :You should disable ``Prevent account creation`` if you are blocking an IP you know to be used by multiple people who might not be responsible, so they will not be caught in the IP block if they register an account (usually except schools where  can be chosen as a block reason and where account creation would probably result in further vandalism). It's whats called a ``softblock``. Another scenario is range-blocking - if you have to block a range of IPs, it might be a good idea to allow account creation for those users who were caught in the range-block. Specifically for UAA, it should only be used if you have indication the user chose the username in bad faith, to disrupt or vandalize. If you are blocking someone who just made a mistake when registering the name, they should be able to register a new name. HTH '  ::To Juliancolton: Nice tip of course but EasyBlock is not always flexible and an admin needs to understand Special:Block without it . ' `