Standardised codes from Recommendation 20, mantained by UNECE.

Data Generation

1. Put the newest Rec20*.xls file into scripts/resources and delete old xml files
2. Run gradlew clean generateData in the project root
3. Commit the generated files in the data folder
4. Tag the version with the name of the used Excel file (e.g. Rec20rev14e-Annex_II-III_2020)