OptionalcalculatedA calculated item: its value is a formula over the field's other items, the cache's.
OptionalcollapsedIts details are not shown.
OptionalhiddenOptionalitemThe index of the item in the cache field's items.
OptionalmissingThe item is no longer in the source; kept until a refresh drops it.
OptionalnameThe caption shown in place of the item's value.
OptionaltypeThe line it is, when not an item of the cache, as OOXML spells it (default, sum, grand…).
One item of a field: an item of the cache field, or a subtotal or grand-total line.