| Field | Field type | Value |
|---|---|---|
| Enclosing_categories | List of Page, delimiter: ; | Patent classification systems |
| Subcategories | List of Page, delimiter: ; | AT 20 • AT 21a • AT 30 • AT 33d • AT 37a • AT 37c • AT 42i • AT 46b • AT 61 • AT 74 • AT 77 • AT 77b • AT 77d |
