"Code","Period Name","Dates"
"EP","Early Prehistoric","9000-2500 BC"
"PeB","Prehistoric Bronze Age","2500-1700 BC"
"PoB","Protohistoric Bronze Age","1700-1000 BC"
"PH","Prehistoric (EP-Geometric)","9000-750 BC"
"Geo","Geometric","1050-750 BC"
"Ar","Archaic","750-475 BC"
"GA","Geometric to Archaic","1050-475 BC"
"Cl","Classical","475-312 BC"
"GAC","Geometric to Classical","1050-312 BC"
"AC","Archaic to Classical","750-312 BC"
"He","Hellenistic","312-100 BC"
"ClHe","Classical to Hellenistic","475-100 BC"
"ER","Early Roman","100 BC-AD 300"
"HER","Hellenistic to Early Roman","312 BC-AD 300"
"LR","Late Roman","AD 300-750"
"REL","Early-Late Roman","100 BC-AD 750"
"Byz","Byzantine","AD 750-1191"
"Med","Medieval","AD 1191-1571"
"Ott","Ottoman","AD 1571-1878"
"Mod","Modern","AD 1878-2000"
"MM","Medieval to Modern","AD 1191-2000"
"HA","Historical Antiquity (Ar-LR)","750 BC-AD 750"
"Hi","Historical (Ar-Mod)","750 BC-AD 2000"
"PC","Post Classical (He-Mod)","312 BC-AD 2000"
"Unk","Unknown","9000 BC-AD 2000"