A named collection of rating parameters and lookup behaviors. A named collection of location, rating template, temporal lookup behaviors, update settings, and rounding specifications. A dated rating consisting of a single lookup table or a single formula with specified parameter units. An alias for simple-rating. A rating created by connecting inputs and outputs of two or more existing ratings to form a rating with a new parameters-id. A rating created by specifying which (or which combination) of existing ratings with identical parameters-ids are used based on values of the input parameters. A stage;flow rating that utilizes the USGS-style lookup interpolation using stage shifts and/or logarhithmic interpolation offsets. A collection of rating templates, rating specifications, and ratings of various types.