Here's a run down of most of the USDM codes (I'm not sure on the codes for pre-86):
79-82: BT2 CVCC Carb
83-85: ET2 SOHC Dual Sidedraft Carb
86-87 Base: A18A1 SOHC Dual Sidedraft Carb
86-87 2.0Si: A20A1 SOHC
88-90 2.0S: B20A3 SOHC Dual Sidedraft Carb
88-91 2.0Si: B20A5
90-91 Si: B21A1
92-96 S: F22A1 SOHC
92-96 Si: H23A1
93-96 VTEC: H22A1
97-01 all: H22A4

all are DOHC Fuel Injected unless otherwise noted.