Message SAP WM378 - Char. & (&) does not have alphanum. single vals.; comparison not possible

Diagnosis
Status: Rel 1.1
The classification comparison in assortment control can only comparecharacteristics and values of the material and assortment with eachother directly as alphanumeric constants.

Examples
Characteristic Values
Material COMPOSITION 10
Assortment COMPOSITION 10
20
The following is not possible:
Characteristic Values
Material COMPOSITION 10.2
Assortment COMPOSITION 10 - 12

System Response
Comparison always results in positive values.