@unitCode
The unit of measure that applies to the Net Weight.
- Example value
 KGM- Code lists
 - Recommendation 20, including Recommendation 21 codes - prefixed with X (UN/ECE)
 - Rules
 - 
            
    
Identifier/Error message Flag PEPPOL-T125-B20102 
Value MUST be part of code list 'Recommendation 20, including Recommendation 21 codes - prefixed with X (UN/ECE)'.fatal