Directory 

The directory is a table containing a variable number of fourteen character entries; a field separator character terminates the table. Each directory entry corresponds to an occurrence of a data field in the record and is divided in five parts:  

Here is an example of a directory entry:  

300003300028910 In this example the tag encoded in the first three digits is '300', signifying that the datafield identified here is a Name of Person. The next four digits are '0033' showing that the datafield is of 33 characters in length. '000289' shows that the datafield begins two-hundred eighty-nine characters after the base address of the data, The digit '1' shows that this datafield belongs to the second segment of the record; datafield belonging to the primary segment will carry the segment identifier '0'. The final digit, '0', indicates that this is first occurrence of a datafield tagged 300 in segment 1.