Hayes Microcomputer Products PC Card - Manual (Page 8)

DIVA T/A PC Card Reference Guide 8
What is EZ-ISDN/IOC?
We highly recommend that you use our toll free ISDN ordering
service to make sure you get the correct ISDN line the first time. The
service is free to our customers.
EZ-ISDN / IOC simplifies the ordering of your ISDN line. It lets you
use simple codes to order pre-configured packages of ISDN features
and services.
The North American ISDN User's Forum (NIUF) and Local Exchange
Carriers (LEC) administer the assignment of codes. Bellcore
administers the National ISDN Ordering Code (IOC) process.
We recommend the use of the following ISDN Ordering codes:
When ordering your ISDN line, use these codes depending on which
method your ISDN provider supports:
EZ-ISDN: Use ordering code 1
IOC: Use ordering code R