Leader/18 Descriptive cataloging form

Character position definition and scope:

The Descriptive cataloging form character position contains a one-character alphanumeric code that indicates characteristics of the descriptive data in the record through reference to cataloging norms. Subfield $e (Description conventions) of field 040 (Cataloging Source) may be used to further identify the specific cataloging rules used.

The code particularly indicates whether the descriptive part of the record exemplifies the rules of the International Standard Bibliographic Description (ISBD), either within or outside of the framework of the Anglo-American Cataloguing Rules, 2nd Edition (AACR 2).

Record requirements (National-level and Minimal-level) for Leader/18 for all types of material: Mandatory.

Validity by material type: Leader/18 and its codes in the table below are valid for all types.

Code:	Descriptive cataloging form description:
#	Non-ISBD
a	AACR 2
c	ISBD punctuation omitted
i	ISBD punctuation included
n	Non-ISBD punctuation omitted
u	Unknown

Content designator history:

Code c - ISBD punctuation omitted [new, 2010]

Code i - ISBD [redefined, 2010]

Code n - Non-ISBD punctuation omitted [new, 2016]

Code p (Record is in partial ISBD form) is obsolete. Defined 1974-1987. Treat as code i (ISBD) for current processing.

Code r (Record is in provisional form) is obsolete. Defined 1976-1981 for cataloging done according to AACR 1, chapter 12 revised. Treat as code i (ISBD) for current processing.

For information on other Leader positions, select:

Leader