A tibble with the columns:
- item_name: The column name.
- item_group: First part of the column name, up to an underscore.
- item_class: The last class value of an item (e.g. numeric, factor).
- item_label: The comment attribute of the column.
- value_name: In case a column has numeric attributes, the attribute names.
- value_label: In case a column has numeric attributes or T/F-attributes,
the attribute values.
In case a column has a levels attribute, the levels.