Is this field derived? i.e. generated from a function.
The kind of this field.
OptionaloffsetFor non derived fields, this is the ordinal position of the field within a positional serialization.
Is this field optional? Note, logical fields will be treated as boolean optionals.
OptionalrankDefined if this is an array, with the rank (how many nested arrays/dimensions are there)
The type reference for this field as an ID, which can be used to look-up a schema.
A reference field.