A key that indicates the aggregation method used for frequency aggregation. This parameter has no affect if the frequency parameter is not set.

The FRED frequency aggregation feature converts higher frequency data series into lower frequency data series (e.g. converts a monthly data series into an annual data series). In FRED, the highest frequency data is daily, and the lowest frequency data is annual.

Order Tags by values of the specified attribute.

Order results by values of the specified attribute.

Represents the type of search to perform.

Sort results is ascending or descending observation date order.

A key that indicates a data value transformation.