255 Cartographic Mathematical Data

Field definition and scope:

Field 255 contains mathematical data associated with cartographic material, including a statement of scale, statement of projection and/or a statement of bounding coordinates. The coordinates can represent a bounding rectangle, the outline of the area covered, and/or the outline of an interior area not covered. For celestial charts, it may also contain a statement of zone, declination data, and/or right ascension data, and/or equinox. The mathematical data in this field may also be recorded in coded form in field 034 (Coded Cartographic Mathematical Data).

The National level record requirement for this field is Mandatory if applicable.

Field 255 is repeatable.

Guidelines for applying content designators:

The data in this field are customarily entered as specified by various cataloging rules. In records formulated following cataloging rules based on International Standard Bibliographic Description (ISBD) principles, a relationship exists between prescribed ISBD punctuation and the identification of specific subfield data. AACR 2 formulated bibliographic records follow ISBD principles for description and punctuation. Most of the examples in this section illustrate the prescribed ISBD punctuation associated with specific subfields.

For indicator and subfield code definitions and examples, National-level (NLR) and Minimal-level (MLR) record requirements, and designator repeatability, see table below:

Position	Description	NLR	MLR	Repeatability
Field 255	Cartographic Mathematical Data	A	A	R
Indicator:
First	Undefined; contains a blank	M
Second	Undefined; contains a blank	M

Subfield code:
$a	Statement of scale	M	M	NR
$b	Statement of projection	A	A	NR
$c	Statement of coordinates	A	A	NR
$d	Statement of zone	A	O	NR
$e	Statement of equinox	A	O	NR
$f	Outer G-ring coordinate pairs	A	O	NR
$g	Exclusion G-ring coordinate pairs	A	O	NR
$6	Linkage	A	A	NR
$8	Field link and sequence number	O	O	R

Input conventions:

Punctuation