Basic Structure
A ISO 2709 record has three sections:
- Record label—the first 24 characters of the record. This is the only portion of the record that is fixed in length. The record label includes the record length and the base address of the data contained in the record. It also has data elements that indicate how many characters are used for indicators and subfield identifiers. (See Variable fields, below)
- Directory—the directory provides the entry positions to the fields in the record, along with the field tags. A directory entry has four parts and cannot exceed nine characters in length:
- Field tag (3 characters)
- Length of the field
- Starting character position of the field
- (Optional) Implementation-defined part
- Datafields (Variable fields)—a string containing all field and subfield data in the record
- Record separator—a single character (IS3 of ISO 646)
Note that although tags are often displayed as labels on bibliographic fields and each bibliographic field has an associated tag, the tags are stored in the directory not in the bibliographic field.
Read more about this topic: ISO 2709
Famous quotes containing the words basic and/or structure:
“Good shot, bad luck and hell are the five basic words to be used in a game of tennis, though these, of course, can be slightly amplified.”
—Virginia Graham (b. 1912)
“I’m a Sunday School teacher, and I’ve always known that the structure of law is founded on the Christian ethic that you shall love the Lord your God and your neighbor as yourself—a very high and perfect standard. We all know the fallibility of man, and the contentions in society, as described by Reinhold Niebuhr and many others, don’t permit us to achieve perfection.”
—Jimmy Carter (James Earl Carter, Jr.)