Code list for digital glacio-geological database:
General		Data type		Sample material
Don't Read	%NR	Elevation	%TE	Bivalves	%SB
Uncorrected Age:		Sub-aerial	%TA	Penguin Remains, bones, guano	%SP
-Coeval	%UC	Fluvial	%TW	Snow Petrel
-No older than	%UA	(Glacio) Marine	%TR	Stomach Oil deposit	%SS
-No younger than	%UB	Sub ice sheet	%TI	(total) organic carbon	%SO
-Oldest	%UO	(Sub) Ice shelf	%TF	Acid Insoluble Org. M.	%SO
-Youngest	%UY	Lacustrine	%TL
		Ice rafting	%TZ	Shells	%SH
Corrected Age:				Algae	%SA
-Coeval	%CC	Margin position (land-ice)	%TM	Sediment	%ST
-No older than	%CA	Grounding line (ice-water)	%TG	Rocks	%SR
-No younger than	%CB	Sub calving line	%TC	volcanic	%SV
-Oldest	%CO	Calving front within 600m	%TQ	boulders	%SU
-Youngest	%CY	Lacustrine-marine transition	%TU	striated bedrock	%SQ
Elevation	%EL	Lake level	%TV	Sealskin	%SK
Elevation above present ice	%EI	Marine-lacustrine transition	%TN	Elephant seal	%SE
Latitude	%LT	Sea level	%TS	Living organism (CaC)	%SL
Longitude	%LG	Sea level from stormbeaches 4m a.s.l.	%TT	Ice penetrating radar + modelling	%SM
		Ice shelf moraine	%TD	Moss	%SZ
		Ice flow line from Ross Island to Taylor Valley	%TO	(Vertebrate) bone	%SN
				Eggs of Branchirecta Gainii	%SX
				Freshwater sediment/organisms (unspecified)	%SF
		Inconsistent	%TX	Marine sediment/organisms (unspecified)	%SI