rick,
Well, this feature is allowed on PRIs, but only if the carrier allows it.
They may also have a way to block your Caller-ID with what was commonly referred to as Star Codes in the US, but that would show up as Blocked Caller-ID versus showing No Caller-ID.
If you want to show No Caller-ID then you will need to ask a few questions from the Carrier first.
Do you allow us to control the Calling Party Number for Outbound Calls?
If they do then you will need to make sure you are configured to do that.
Next you will need to ask them if they allow for a blank Calling Party Number for Outbound Calls. In the US this is typically only allowed for certain types of customers; i.e. Police Departments.
Thanks,
TE