AS1 Aston Cadet
AS2 Aston Club
AS3 Aston National
AS4 Aston Historic
AS5 Aston GP

BL1 Blackwood GP
BL2 Blackwood Rallycross

FE1 Fern Bay Club
FE2 Fern Bay Green
FE3 Fern Bay Gold
FE4 Fern Bay Black
FE5 Fern Bay Rallycross
FE6 Fern Bay RallyX Green

KY1 Kyoto Oval
KY2 Kyoto National
KY3 Kyoto GP

SO1 South City Classic
SO2 South City Sprint1
SO3 South City Sprint2
SO4 South City Long
SO5 South City Town

WE1 Westhill International

AU1 Autocross

If there's R after the code, for example AS1R it means it's Reversed track.