100 - Operator Assitance  
  112 - Emergency services (Euro standard number)
 1170 - Sprint DMS100 test message
  123 - At the third stroke...
  125 - ? ..Anyone?
  131 - Mercury (Test pin - 1234567)
  132 - Mercury
  133 - Mercury Calling Card
  134 - ? Anyone?..
  141 - Withold Number.
  143 - ? Anyone?
  144 - BT Charge card.
 1470 - Release CLI
 1471 - Number of last person who called
 1474 - Access Withdrawn  (Formerly callback)
  150 - BT customer service (What customer service ? :)
  151 - BT Faults (Home)
  152 - BT Customer Enquiries
  153 - International Directory Enquiries
  154 - BT faults (Buisiness)
  155 - International Operator (Con em into dialing inwards :)
 1571 - Call minder (Urghhh.. )
 1601 - ? Anyone ? 1602 - ? Anyone ?
 1611 - ? Anyone ? 1616 - ? Anyone ?
 1619 - Energis Card Service (Voice recognition )
 1620 - Energis 1621 - Energis
 1630 - NSS Metrocall (0800 376 7766)
 1631 - NSS Metrocall
 1636 - ? (Contact service provider?.. Hmmmm)
 1637 - (I think 1636 and 1637 are NSS? )
 1639 - NSS metrocall 1656 - Telia
 1660 - Worldcom (0500 20 3000) 
 1661 - Worldcom 
 1666 - Worldcom 
 1670 - Sprint
 1678 - Sprint
17070 - ANI Test Number - Press 1 for Ringback and hang up
17094 - ? Anyone?
17095 - Anyone ?
17099 - Emergency services back door
  175 - On updated exchanges will timeout for 190 seconds
  176 - Line status Dial area code + Number (Works only on local exchange)
 1810 - Telstra.
 1811 - ?.. 0800 883355 24 hr customer service (I never checked yet! :)
 1812 - Telstra. 
 1818 - ? Anyone ?
  190 - BT Telegrams (Changed to 0800 190190)
  192 - Directory Enquiries.
  195 - Directory Enquiries (For the Blind)
  198 - Operator Assistance (For the Blind)