Includes information about the physical instance of a data product (an actual data file). It completes the documentation contained in the Physical Data Product module that is specific to the individual file and serves as a descriptive record of the external data file. Physical Instance provides a citation for the data file, a link to the RecordLayout(s) used by the files records, a description of it coverage (as a constraint if different from the study), check figures for quality control (e.g. digital fingerprint, record count, etc.), and a statistical summary of the data in the file at both the variable and category level.