Output Data Set Prefix The Output Data Set Prefix field is used to specify a prefix to be appended to the name of the output SAS data set. If no prefix is specified here, the name of the input data set is specified by default. For detailed information about the files and data sets used or created by JMP Life Sciences software, see Files and Data Sets. To Specify a Prefix for the Output Data Set: Left-click in the field and enter a prefix for the output data set.