See also ICS BiblioSelect for bibliographies of these topics and sites.

Material
ARC = Architecture
COI = Coin
INS = Inscription
GG = Gold Glass
GS = Gem/Seal
LMP = Lamp
MOS = Mosaic
MP = Map/Plan
PAI = Painting
PC = Plate/Cup
POT = Pottery
SAR = Sarcophagus
SCE = Scenic
SCU = Sculpture
SIT = Site

JC = Jewish Catacombs (Rome)
CC = Christian Catacombs (Rome)
CO = Catacombs Outside Rome
CYP = Cypriot
CYC = Cycladic
GRE = Greek
ET = Etruscan (Tarquinia, Cerveteri, Vulci)
AI = Ancient Israel (Hammat Tiberias, Beth Alpha, Beth Shean, Capernaum, Jerusalem)
MIN = Minoan
NE = Near Eastern (Assyrian, Babylonian, Hittite, Mesopotamian, Sumerian, Syrian, Ugaritic, Phoenician, Anatolian, Persian)
EG = Egyptian (Old Kingdom, First Intermediate Period, Middle Kingdom, Second Intermediate Period, New Kingdom, Third Intermediate Period, Late Period, Ptolomaic, Roman).

Jewish Catacombs (Rome)
MV = Monteverde
TOR = Villa Torlonia
RAN = Vigna Randanini
LAB = Via Labicana

Christian Catacombs (Rome)
AUR = Aurelii (Viale Manzoni)
COM = Commodilla
CAL = Callisto
CYR = Cyriaca
DOM = Domitilla
GIO = Giordani
SMP = Marcellinus and Peter
PAM = Pamphilius
PRE = Pretestato
PRI = Priscilla
SS = Sebastiano
VA = Via Anapo
LAT = Via Latina (via Dino Compagni)

Catacombs/Burial Sites Outside Rome
ALE = Alexandria (Egypt)
BET = Beth She'arim
JER = Jerusalem
MAL = Malta
NAP = Naples
PAL = Palmyra
SAB = Sabratha
SAR = Sardinia
SIC = Sicily
TUN = Tunisia
VEN = Venosa

Other Sites
CAR = Carthage
HER = Herculaneum
GRE = Greece (Athens, Corinth, Delphi, Olympia)
OST = Ostia
PAE = Paestum
POM = Pompeii