The curation of controlled vocabularies at museum-digital takes place in a centralized manner. All museums of all instances of a given primary language work together to create a common database of controlled terms. Since curating controlled vocabularies is time consuming, we try to reduce the participating museums\' workload in this regard as much as possible. Besides, a centralized curation of controlled vocabularies leads to more uniform results.

To ease the curation, we have developed a tool, "nodac", which automatizes much of the enrichment work and offers a simple interface for positioning terms hierarchically. With this tool, norm data editors, can also use batch editing functionalities for enhancing the controlled vocabularies.

The curation of controlled vocabularies is thus a joint effort of the participating museums, direct volunteering, and support by a number of state governments, led by a small team of "norm data editors".

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