Thanks, kwired. Just what I needed - and in a flash!
Interesting to see how the Code has evolved in three decades.
From 2011 NEC:
518.4 Wiring Methods.
(A) General. The fixed wiring methods shall be metal raceways, flexible metal raceways, nonmetallic raceways encased in not less than 50 mm (2 in.) of concrete, Type MI, MC, or AC cable. The wiring method shall itself qualify as an equipment grounding conductor according to 250.118 or shall contain an insulated equipment grounding conductor sized in accordance with Table 250.122.
Exception: Fixed wiring methods shall be as provided in
(a)
Audio signal processing, amplification, and reproduction equipment ? Article 640
(b)
Communications circuits ? Article 800
(c)
Class 2 and Class 3 remote-control and signaling circuits ? Article 725
(d)
Fire alarm circuits ? Article 760
(B) Nonrated Construction. In addition to the wiring methods of 518.4(A), nonmetallic-sheathed cable, Type AC cable, electrical nonmetallic tubing, and rigid nonmetallic conduit shall be permitted to be installed in those buildings or portions thereof that are not required to be of fire-rated construction by the applicable building code.
Informational Note: Fire-rated construction is the fire-resistive classification used in building codes.
(C) Spaces with Finish Rating. Electrical nonmetallic tubing and rigid nonmetallic conduit shall be permitted to be installed in club rooms, conference and meeting rooms in hotels or motels, courtrooms, dining facilities, restaurants, mortuary chapels, museums, libraries, and places of religious worship where the following apply:
(1)
The electrical nonmetallic tubing or rigid nonmetallic conduit is installed concealed within walls, floors, and ceilings where the walls, floors, and ceilings provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire-rated assemblies.
(2)
The electrical nonmetallic tubing or rigid nonmetallic conduit is installed above suspended ceilings where the suspended ceilings provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire-rated assemblies.
Electrical nonmetallic tubing and rigid nonmetallic conduit are not recognized for use in other space used for environmental air in accordance with 300.22(C).
Informational Note: A finish rating is established for assemblies containing combustible (wood) supports. The finish rating is defined as the time at which the wood stud or wood joist reaches an average temperature rise of 121?C (250?F) or an individual temperature rise of 163?C (325?F) as measured on the plane of the wood nearest the fire. A finish rating is not intended to represent a rating for a membrane ceiling.
------------------------------------------
From 1987 NEC:
518-4. Wiring Methods. The fixed wiring methods shall be metal raceways,
nonmetallic raceways encased in not less than 2 inches (50.8 mm) of
concrete, Type MI cable, or Type MC cable.
Exception No. 1: Nonmetallic-sheathed cable, Type AC cable, and rigid
nonmetallic conduit shall be permitted to be installed in those buildings or
portions therof that are not required to be fire-rated construction by the
applicable building code.
------------------------------------
1987 had a second exception that I did not copy that had similar information to what is in the exception after part A in 2011
