---+ Inventory/Scan Request

This request returns a (sorted) list of distinct values for a requested concept. In DiGIR the inventory request as well as the scan request in BioCASE allow up to now only to query for a single concept.

See the DifferencesInScanOperations for the different protocol aspects.

---+++++ Desired Scan Features

   * paging through the result set, if providers limit the number of returned items
   * scan combined multiple concepts as in SELECT DISTINCT in SQL.
   * allow filters to work with scans
   * allow to only count the number of distinct values (See CountRequest for a possible seperate request method)

---+++++ Proposed Inventory

   * InventoryProposalOne
   * InventoryProposalTwo