Leader
Field definition and scope:
The Leader is the first field of a classification data record. It is fixed in length at 24 character positions (00-23). The Leader consists of data elements that contain numbers or coded values that define the parameters for the processing of the record. Alphabetic codes are entered in lowercase.
Character positions 20-23 comprise the Entry map for the Directory . They contain four one-character numbers that specify the structure of the entries in the Directory. More detailed information about the structure of the Leader is contained in USMARC Specifications for Record Structure, Character Sets, Tapes.
The Leader has no indicators or subfield codes ; the data elements are positionally defined.
Leader character positions:
For details on Leader character positions and codes, select a topic:
Leader/00-04 Logical record length
Leader/07-09 Undefined character positions
Leader/12-16 Base address of data
Leader/18-19 Undefined character positions
Related USMARC fields or documents:
008/10 Record update in progress
USMARC Specifications for Record Structure, Character Sets, Tapes
See also:
USMARC Format for Classification Data: Contents
