When a specific parameter is incremented in a series, to assign it we use an array of values of this parameter assigned to a series of datasets.
Loading parameters into datasets assigned to a series is easier. Since (usually) many parameters between datasets in a series are linked, you need to load values and ranges for all parameters into just one dataset in the series using assign_parameter_values() and then execute transfer_all_parameters_to_individual_datasets() to propagate common parameter values/ranges to all other datasets. The parameters that are different in the series may be loaded as an array using assign_unlinked_parameter_in_series(). It will take an array of values and min/max limit for the parameter and will assign them into each dataset using the same sequence the datasets appear in the output of show_series_datasets(). In practice one may organize different datasets into the series with the only purpose to use these parameter assignment mechanism, while treating datasets as completely independent otherwise.
For a specific usage see TotalFit.m