File 01—File Linking Fields (comma delimited). These fields link File 01 with the geographic header. Data dictionary Field name reference Max Data Name size type File Identification FILEID 6 A/N State/U.S. Abbreviation (USPS) STUSAB 2 A Characteristic Iteration CHARITER 3 A/N Characteristic Iteration File Sequence Number CIFSN 2 A/N Logical Record Number LOGRECNO 7 N P1. TOTAL POPULATION [1] Universe: Total population Total P0010001 01 9