Seems like more people are familiar with the concept of abbreviated dialing designations because of Mary J. Blige than anything the FCC has put out. Still, the FCC has put together a very nice summary explaining Abbreviated Dialing Codes (sometimes referred to as N11) that is worth a read from those working in the public sector.
More and more state governments are starting to implement systems based on N11 designations – the State of Utah has a VoiceXML-based 511 system, as does the State of Virginia (I believe both are using the TellMe platform). The State of Oklahoma is now doing some interesting things with 211.
Rollout of systems based on these designations is still somewhat uneven — organizations advocating for the adoption of 511 and 211 systems track implementations closely. Let’s hope that as more and more states deploy systems, they will build them using open standards. Mary’s got no love for vendor lock in.