Directory (NR)
      
      MARC 21 LITE Bibliographic
      
         					April 2008
         				
      
      
      Computer-generated index to the location of the variable control and data fields within
         a record. The Directory immediately follows the Leader at character position 24 and
         consists of a series of fixed-length (12 character positions) entries that give the tag,
                     length, and starting character position of each variable field.
      
       [Link to MARC 21 Concise
                                 Formats]
      
 Character Positions00-02 - Tag  Three ASCII numeric or ASCII alphabetic characters (upper case or lower case, but
                              not both) that identify an associated variable field.
         
       
      03-06 - Field length  Four ASCII numeric characters that specify the length of the variable field,
                              including indicators, subfield codes, data, and the field terminator. A Field
                              length number of less than four digits is right justified and unused positions
                              contain zeros.
         
       
      07-11 - Starting character position  Five ASCII numeric characters that specify the starting character position of the
                              variable field relative to the Base address of data (Leader/12-16) of the record.
                              A Starting character position number of less than five digits is right justified
                              and unused positions contain zeros.