CSV / TSV

CSV (Comma Separated Value) is a very common format.  It is described here:

Up to 3 CSV files can be specified.  The order in which they are specified is important.  When applying a saved project file to new CSV data files, each of the files must have at least the same columns as the original files used to create the project file.

TSV (Tab Separated Value) works exactly like CSV, except that the delimiter between columns is a tab instead of a comma.