BEAst: unitCode refers to T6706. Peppol: The unit of measure that applies to the measure.

Example value
LTR
Code lists
Recommendation 20, including Recommendation 21 codes - prefixed with X (UN/ECE)
Rules
Identifier/Error message Flag
PEPPOL-T120-B23702
Value MUST be part of code list 'Recommendation 20, including Recommendation 21 codes - prefixed with X (UN/ECE)'.
fatal