SB	State border
SN	State
IL	Inhabited location
LA	Lake
RI	River
AP	Airport
NB	National border
AV	Active volcano
VO	Volcano
MR	Mountain range
MO	Mountain
IC	Impact crater
AA	Crater
AL	Albedo Feature
CA	Chain of craters
DO	Ridge
LF	Feature near landing site
LG	Ringed feature
LC	'Lake'
LS	Landing site
ME	'Sea'
MN	Cliff
OC	'Ocean'
PT	Plateau
PA	'Marsh'
PR	Promontory
RM	Fissure
SI	Small plain
VA	Valley
PL	Low plain
RU	Scarp
XX	Empty