A complete Telco list of Vertical Service Codes (star codes) is listed here:

http://www.nanpa.com/number_resource...finitions.html
http://www.nanpa.com/number_resource...signments.html

Not all of the defined services are applicable in a VoIP environment (and some important services are not accounted for). I would submit that this is a good starting point.

In addition, just because NANPA has indicated a de-facto standard, does not mean that any company is required to follow suit.

Regards,
Norm