NEC Article 334: NM cable (Type NM, NMC, NMS) for residential wiring. 334.10 uses permitted: Types I-V construction (originally limited to Types III-V, expanded in recent editions). Not permitted in commercial above 3 stories. 334.12 not permitted: exposed in dropped/suspended ceilings in commercial, any hazardous location, embedded in poured concrete. 334.15 exposed work: follow surface, protect with conduit where subject to damage. 334.23 conductor types: THHN/THWN-2 insulation. 334.30 securing: within 12in of every box, every 4.5ft along run. Staples: flat staple over cable (do not damage sheath). 334.80 ampacity: follow Table 310.16 at 60C column for NM cable (even though conductors are rated 90C, the cable jacket limits to 60C). Common sizes: 14/2 (15A lighting), 12/2 (20A receptacles), 10/3 (30A dryer), 6/3 (50A range).