For each concept, we need at least the URI of the concept and the label available. The label is necessary to define the search term for a given concept. To support more than one language we would need more than one label like in index/core properties:

The example demonstrates to valid concepts URL. Without a label, the search term is not derivable for both.
For each concept, we need at least the URI of the concept and the label available. The label is necessary to define the search term for a given concept. To support more than one language we would need more than one label like in index/core properties:
The example demonstrates to valid concepts URL. Without a label, the search term is not derivable for both.