Here's the rest of the story

[jtedesco1]

210.12 Arc-Fault Circuit-Interrupter Protection.

(A) Definition: Arc-Fault Circuit Interrupter.

An arc-fault
circuit interrupter is a device intended to provide protection
from the effects of arc faults by recognizing characteristics
unique to arcing and by functioning to de-energize the circuit
when an arc fault is detected.

(B) Dwelling Unit Bedrooms.

All 120-volt, single phase,
15- and 20-ampere branch circuits supplying outlets installed
in dwelling unit bedrooms shall be protected by a
listed arc-fault circuit interrupter, combination type installed
to provide protection of the branch circuit.

Branch/feeder AFCIs shall be permitted to be used to
meet the requirements of 210.12(B) until January 1, 2008.

FPN: For information on types of arc-fault circuit interrupters,
see UL 1699-1999,

Standard for Arc-Fault Circuit
Interrupters.

Exception: The location of the arc-fault circuit interrupter

shall be permitted to be at other than the origination of the
branch circuit in compliance with (a) and (b):

(a) The arc-fault circuit interrupter installed within
1.8 m (6 ft) of the branch circuit overcurrent device as
measured along the branch circuit conductors.

(b) The circuit conductors between the branch circuit
overcurrent device and the arc-fault circuit interrupter
shall be installed in a metal raceway or a cable with a
metallic sheath.