All the tsv-files for the custom metadata blocks will be stored here.
Each tsv-file need to have a corresponding properties file with all the strings in there that can then also be translated to Dutch for instance.
The explanation is here: https://guides.dataverse.org/en/latest/admin/metadatacustomization.html.
Better copy from other sources; like the DANS Datastations code.
For the DANSMetadata we have used the dansRights from dans-cores-systems in provisioning/files/custom-metadata-block-properties.
Especially the controlledvocabularies can be a hassle, and some form of automation would be helpful.
Note that the properties files are input for the translation repository (TranslationDataverseUI)!