Leader/12-16 Base address of data (Leader)
The Base address of data character positions contain a five-character numeric string that indicates the first character position of the first variable control field in the record. The number is right justified and each unused position contains a zero (0).
The number is the base from which the starting character position of all the other fields in the record is addressed in the Directory . (The starting character position in the Directory entry for each field of the record is relative to the first character of the first variable control field rather than the beginning of the record.) The Base address of data is equal to the sum of the lengths of the Leader and the Directory, including the field terminator character at the end of the Directory.
The Leader/12-16 elements are usually system generated.
Related USMARC fields or documents:
For information on other Leader character positions, select:
