0 – Operator assistance
00 – Long-distance operator assistance
011 – International Access Code. (For all destinations outside the NANP)
01 – International Access Code using operator assistance. (For all destinations outside the NANP)
10x xxxx – Used to select use of an alternative long-distance carrier
211 – Community information or social services (In some cities), formerly payphone refund line (and prior to that, used to access “long distance” operators in some cities)
311 – City government or non-emergency police matters such as noise complaints, suspicious people, minor injuries and non-working streetlights and parking meters, etc. (In some cities)
411 – Local telephone directory service (Some telephone companies provide national directory assistance)
511 – Traffic, road, and tourist information or reads back the number you are calling from (i.e. drop line ID) (In some cities and states)
611 – Telephone line repair service (Some telephone companies use this instead of 4104 or 811). Also used by mobile telephone companies to reach customer service
711 – Relay service for customers with hearing or speech disabilities
811 – “Dig safe” underground pipe safety line in the United States, non-urgent telehealth services in Canada, formerly telephone company business office, mainly to encourage people not to hit telephone or power lines when they dig.
911 – Emergency dispatcher for fire department, ambulance, police etc.
830 or 958 or 9580 or 998 – Returns the number on the line via a recorded voice (in some areas)
(Area Code) + 555-1212 – Non-local directory service