I can see some cross cultural terminology - Hopefully it won't lead to too much confusion...
Earth has been removed from our dictionary...
So to speak.... "Earthing" isn't in our lexicon...
Welcome to the forum none-the-less but you may want to refer to some of this in our common terminology. "Grounding" and conversely "Bonding"
Take a peek here too...
http://forums.mikeholt.com/showpost.php?p=656116&postcount=37
Anyway the codes here 'require' certain connections, and 'allow' certain connections in the respect to the connection between the neutral (Grounded conductor) and 'grounding' conductors.
The NEC "requires" the bond between the Grounded and Grounding conductors in the main disconnecting means... The Main Bonding Jumper. (MBJ)
However - (and IMO contrary to intent of single point grounding) "allows" certain enclosures to be "Grounded" by the grounded service conductor - e.g. meter enclosures. In a political sense conductors prior to the main disconnect are under two sets of rules as well - the utility providing power - who may also require that the connection be made there, and the NEC which allows it to be made there.
Bottom line is you will "always required to have a MBJ in the main disconnect" and you may have a similar connection in the meter enclosure, and possibly be required to have that connection as well, acting as both a grounding and bonding means for that enclosure.
I'm sure someone will have a better way to put that - or correct me...