565 CASE FILE CHARACTERISTICS NOTE (R)Indicators First Display constant controller ^ No information provided 0 Case file characteristics 8 No display constant generated Second Undefined; contains a blank (^)Subfield Codes $a Number of cases/variables (NR) $b Name of variable (R) $c Unit of analysis (R) $d Universe of data (R) $e Filing scheme or code (R) $3 Materials specified (NR) $6 Linkage (NR) $8 Field link and sequence number (R)