"Datecode","Detail","datecatchall","catchallcode"
"AN","Anglo-Saxon, Scandinavian AD850 - 1100","Saxon","60"
"AO","late 9th-early 12th century","Saxon","60"
"AT","late 2nd-early 3rd century","Roman","50"
"BA","Bronze Age (broad category)","Bronze Age","30"
"BB","Beaker/early Bronze","Bronze Age","30"
"BE","Beaker (neolithic/early Bronze Age)","Bronze Age","30"
"BI","Bronze Age/Iron Age transition","BA/IA","35"
"BL","mid-late Bronze Age","Bronze Age","30"
"DD","7th-8th century","Saxon","60"
"DE","Devensian","Palaeolithic","00"
"DS","late 15th-mid/late 16th century","Medieval/post-med","75"
"EB","early Bronze Age","Bronze Age","30"
"ED","early/mid Saxon","Saxon","60"
"EE","18th-19th cent","Post-medieval","80"
"EF","11th-14th","Medieval","70"
"EG","early/mid Iron Age","Iron Age","40"
"EH","early/high medieval","Medieval","70"
"EI","early Iron Age","Iron Age","40"
"EL","11th century","Saxon","60"
"EM","early medieval, i.e. AD 1150-1250 or mid C12th to mid C13th AD","Medieval","70"
"EN","early-mid Roman","Roman","50"
"EP","early post-medieval, i.e. AD 1500-1600 or beginning of C16th to beginning of C17th","Post-medieval","80"
"ER","early Roman ?C1st-2nd AD","Roman","50"
"ES","early Saxon, Anglian  or Dark Age (depending on area) AD 400-650","Saxon","60"
"ET","eighteenth century","Post-medieval","80"
"EV","11th-13th century","Medieval","70"
"EZ","early-mid Bronze","Bronze Age","30"
"FD","late 14th-early 15th century","Medieval","70"
"FE","15th century","Medieval","70"
"FF","14th-15th century","Medieval","70"
"FL","Flandrian","Palaeolithic","00"
"FN","14th-early 15th century","Medieval","70"
"FS","mid 15th-early 16th century","Medieval","70"
"FT","14th century","Medieval","70"
"HA","late 1st-early 2nd century","Roman","50"
"HF","13th-15th century","Medieval","70"
"HH","late 13th-early 14th century","Medieval","70"
"HL","high medieval/late medieval","Medieval","70"
"HM","high medieval, i.e. AD 1250-1400 or mid C13th to beginning C15th","Medieval","70"
"HN","14th century to modern","(poorly dated)","00"
"HP","mid 14th-mid 16th century","Medieval","70"
"HT","14th-18th century","(poorly dated)","00"
"IA","Iron Age (broad category)","Iron Age","40"
"IC","1st century AD","Roman","50"
"IE","late Iron Age/early Romano-British","Iron Age/Roman","45"
"IF","13th-14th century","Medieval","70"
"IR","Iron Age/Roman","(poorly dated)","00"
"IV","mid/late 16th-17th century","Post-medieval","80"
"LB","late Bronze Age","Bronze Age","30"
"LE","late medieval/early post-medieval","Medieval/post-med","75"
"LF","late 4th-early 5th century","Roman","50"
"LG","late Bronze Age to mid Iron Age","Iron Age","40"
"LI","Late Iron Age","Iron Age","40"
"LL","late 3rd and 4th century","Roman","50"
"LM","late medieval, i.e. AD 1400-1500 or beginning C15th to beginning C16th","Medieval","70"
"LN","Late neolithic","Neolithic","20"
"LO","Late neolithic/early Bronze","Neolithic/BA","25"
"LP","late post medieval, i.e AD 1600-1750 or beginning of C17th to mid C18th","Post-medieval","80"
"LR","late Roman ?C3rd-4th AD","Roman","50"
"LS","late Saxon","Saxon","60"
"LT","lower Palaeolithic","Palaeolithic","00"
"LU","Late Upper Palaeolithic","Palaeolithic","00"
"LV","late medieval to recent","(poorly dated)","00"
"MA","mid-late Iron Age","Iron Age","40"
"MB","middle Bronze Age","Bronze Age","30"
"MD","medieval (broad category)","Medieval","70"
"MF","mid 1st-mid 4th century","Roman","50"
"MI","mid Iron Age","Iron Age","40"
"ML","mesolithic","Mesolithic","10"
"MM","late post-medieval-early modern (17th-19th century)","Post-medieval","80"
"MN","mid-late Roman","Roman","50"
"MO","modern (post-dated AD 1750)","Post-medieval","80"
"MP","medieval-early post-medieval (14th-16th century)","Medieval","70"
"MR","mid Roman ?C2nd-3rd AD","Roman","50"
"MS","middle Saxon (including Anglian) AD 650-850","Saxon","60"
"MT","mid 1st-late 3rd century","Roman","50"
"MX","mid-late Saxon","Saxon","60"
"NB","late Neolithic-mid Bornze","Neolithic/BA","25"
"ND","not dated, either because dating is too broad, too vague or not reported","(poorly dated)","00"
"NE","neolithic","Neolithic","20"
"NF","9th-15th century","Medieval","70"
"NI","9th century","Saxon","60"
"NM","Saxo-Norman to medieval (i.e. c.11th-15th century)","Medieval","70"
"NN","19th century","Post-medieval","80"
"NT","9th-early 10th century","Saxon","60"
"PC","Celtic/early Christian (outside Roman influence)","Roman","50"
"PH","prehistoric (very broad category for poorly dated pre Roman sites)","(poorly dated)","00"
"PM","post-medieval (broad category) i.e. AD 1500-1750 or beginning C16th to mid C18th","Post-medieval","80"
"PR","post Roman (very broad category for poorly dated sites)","(poorly dated)","00"
"RB","Romano-British, i.e. native British sites","Roman","50"
"RO","Roman (broad category)","Roman","50"
"RS","Romano-British-Saxon","(poorly dated)","00"
"SA","Saxon (broad category)","Saxon","60"
"SC","6th century","Saxon","60"
"SD","5th-6th century","Saxon","60"
"SE","Post-Roman/migration period/Saxon/AD 400-1150","Saxon","60"
"SF","mid 2nd-mid 4th century","Roman","50"
"SG","16th-18th century","Post-medieval","80"
"SI","16th century","Post-medieval","80"
"SM","Saxon-medieval (10th-13th cent.)","(poorly dated)","00"
"SN","Saxo-Norman (11th-12th century)","Medieval","70"
"SS","16th-17th century","Post-medieval","80"
"ST","9th-10th century","Saxon","60"
"SV","17th century","Post-medieval","80"
"TE","10th-12th century","Saxon/medieval","65"
"TF","12th-14th century","Medieval","70"
"TI","13th century","Medieval","70"
"TL","10th-11th century","Saxon","60"
"TS","mid 13th to early 17th century","(poorly dated)","00"
"TT","10th century","Saxon","60"
"TW","12th century","Medieval","70"
"VC","early 6th-late 7th century","Saxon","60"
"VF","4th-early 5th century","Roman","50"
"VI","late 5th-early 6th century","Saxon","60"
"VL","late 3rd-5th century","Roman","50"
"VP","very late post-medieval (i.e. late 18th-19th century)","Post-medieval","80"
"VR","very late Roman (i.e. late 4th-early 5th century)","Roman","50"
"VS","late 4th-early 6th century","Saxon","60"
"VZ","early 6th-late 7th century","Saxon","60"
"WF","12th-early 14th century","Medieval","70"
"WT","12th-13th century","Medieval","70"
"XL","mid 11th to late 12th century","Medieval","70"
"XS","1533 to 1647","Post-medieval","80"
"XV","1647 to 1750","Post-medieval","80"