"period code","definition"
"BA-IA","Bronze Age and Iron Age"
"BA","Bronze Age"
"IA","Iron Age"
"MBA","Middle Bronze Age"
"LBA","Late Bronze Age"
"EIA","Early Iron Age"
"MIA","Middle Iron Age"
"LIA","Late Iron Age"
"MBA-LBA","Middle Bronze Age and Late Iron Age"
"LBA-EIA","Late Bronze Age and Early Iron Age"
"EIA-MIA","Early Iron Age and Middle Iron Age"
"MIA-LIA","Middle Iron Age and Late Iron Age"
"LIA-ERB","Late Iron Age and Early Romano-British"