Carrier
How the source is sampled into an NTSC composite path.
Which rows (“fields”) of the source image are used.
Low-pass used throughout the effect.
Filter input luminance to reduce rainbow artifacts.
Low-pass the input chrominance before modulation.
Snow & noise
Speckle, composite hiss, and separate luma/chroma grain.
Chroma
Color encoding, delay, and demodulation.
Phase shift of the chrominance signal each scanline. Usually 180°.
Filter used to recover chrominance from the composite signal.
Low-pass the output chroma signal.
Luma & ringing
Horizontal smear and notch-filter ringing.
VHS tape
Tape speed, chroma loss, deck sharpening, and edge wave.
Head switching
Bottom-of-frame VHS head-switch. Stays inside the picture.
Tracking
Tracking error band, usually near the bottom of a bad tape.
Scale
Physical scale of the NTSC path. 480p with horizontal scale 1.0 is the intended reference.