Unit of Measure (UOM) features in ForceField

UOM is the base Unit of Measure, it is the default selling unit
(except for catch-weight items where it is the weight unit e.g. "LB")
All prices are assumed to be in terms of this unit unless they are
in a PRICES record that specifies an alternate UOM.

ALT_UOMS is a CSV list of alternate units for sales or returns
ALT_CONV is a CSV list of the alt. unit conversion factors
Each factor is the number of base UOM's per the corresponding alt. UOM
The factor is multiplied times the price for the base UOM to get
the price for the corresponding alt. UOM

SELL_UOMS is a CSV list of the valid UOMs (from UOM and ALT_UOMS) for sales
RTRN_UOMS is a CSV list of the valid UOMs (from UOM and ALT_UOMS) for returns

Example 1:
an item normally sold by Each
it can also be sold as Box of 8 Each or Case 32 Each (4 Box in a Case)
it can be sold or returned in any unit
UOM = Each
ALT_UOMS = Box,Case
ALT_CONV = 8,32
SELL_UOMS = Each,Box,Case
RTRN_UOMS = Each,Box,Case

Example 2:
an item normally sold or returned by Case (containing 4 Each)
it can also be returned by Each but not sold by Each
UOM = Case
ALT_UOMS = Each
ALT_CONV = 0.25
SELL_UOMS = Case
RTRN_UOMS = Case,Each