USMARC Concise Authority: Leader and Directory
LEADER
A fixed field that comprises the first 24 character positions (00-23) of each record and provides information for the processing of the record.
Character Positions
- 00-04 - Logical record length
The computer-generated, five-character numeric string that specifies the length of the entire record. The number is right justified and each unused position contains a zero. - 05 - Record status
A one-character code that indicates the relation of the record to a file.- a - Increase in encoding level
The Encoding level (Leader/17) of the record has been changed from code o (incomplete) to code n (complete). - c - Corrected or revised
A change other than in the Encoding level code has been made to the record. - d - Deleted (other)
The delete code used when neither code s nor code x is applicable. - n - New
- s - Deleted; heading split into two or more headings
- x - Deleted; heading replaced by another heading
- a - Increase in encoding level
- 06 - Type of record
A code that indicates the characteristics of and defines the components of the record.- z - Authority data
- 07-09 - Undefined character positions
Each contains a blank (#) - 10 - Indicator count
The computer-generated number 2 that indicates the number of character positions used for indicators in a variable data field. - 11 - Subfield code count
The computer-generated number 2 that indicates the number of character positions used for each subfield code in a variable data field. - 12-16 - Base address of data
The computer-generated, five-character numeric string that indicates the first character position of the first variable control field in a record. The number is right justified and each unused position contains a zero. - 17 - Encoding level
A one-character code that indicates whether the record is complete.- n - Complete authority record
The record meets national level record requirements. - o - Incomplete authority record
- n - Complete authority record
- 18-19 - Undefined character positions
Each contains a blank (#) - 20-23 - Entry map
Four computer-generated, single-digit numeric characters that indicate the structure of each entry in the Directory. - 20 - Length of the length-of-field portion
Contains a 4 - 21 - Length of the starting-character-position
portion
Contains a 5 - 22 - Length of the implementation-defined portion
Contains a 0 - 23 - Undefined Entry map character position
Contains a 0
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DIRECTORY
A 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.
Character Positions
- 00-02 - Tag
Three numeric or alphabetic (uppercase or lowercase, but not both) characters that identify an associated field. - 03-06 - Field length
Four numeric characters that indicate the length of the field, including indicators, subfield codes, data, and the field terminator. The number is right justified and each unused position contains a zero. - 07-11 - Starting character position
Five numeric characters that indicate the starting character position of the field relative to the Base address of data (Leader/12-16) of the record. The number is right justified and each unused position contains a zero.