There is a discussion on Github
here, if people would like to put in their 2c.
The current cargo class definitions do not offer a way to differentiate between "clean" and "dirty" cargos. This is particularly an issue for hopper and tanker cars, where it can be hard to differentiate a vehicle for carrying grain from one carrying coal, or one carrying milk from one carrying oil, without resorting to explicit cargo refits and exclusions. It also causes the perennial problem of having to explicitly handle Livestock cargos.
To that end, the proposal is to define two of the three unused Cargo Class bits as "potable / food / clean" and "non-potable / non-food / dirty". Two bits are required, rather than one, because the extended cargo bits should only ever be excluded, not required, for maximum compatibility; and some vehicles may wish to exclude one, the other, or neither (excluding both is probably a bad idea).
Default cargo classes should change as follows:
COAL 4010 Bulk, Dirty
OIL_ 4040 Liquid, Dirty
LVST 4020 Piece, Dirty
GRAI 2010 Bulk, Clean
IORE 4010 Bulk, Dirty
WHEA 2010 Bulk, Clean
FOOD 4084 Piece, Refrigerated, Clean
RUBR 4040 Liquid, Dirty
FRUT 2090 Bulk, Refrigerated, Clean
MAIZ 2010 Bulk, Clean
CORE 4010 Bulk, Dirty
WATR 2040 Liquid, Clean
SUGR 2010 Bulk, Clean
Thoughts / objections to this proposal?
