Siemens has a fairly good overall description of AFCIs

http://w3.usa.siemens.com/us/SiteCo...AFCI-Technical-Overview-Presentation.pdf

I am still not sure I understand all I know about 210.12(A)(3)

Why a arc fault breaker and a device type on the same circuit?
What is a "supplemental arc protection circuit breaker"?
Leviton talks about their device but the breaker is just alluded to.
http://www.bobselectricco.com/bob-s...itarc-faultcircuitinterrupterreceptacle.

Greg Fretwell