255 Cartographic mathematical data area (R)

First and second indicators
# Undefined
Subfields
a Statement of scale (NR)
b Statement of projection (NR)
c Statement of coordinates (NR)
d Statement of zone (NR)
e Statement of equinox (NR)
f Outer G-ring coordinate pairs (NR)
g Exclusion G-ring coordinate pairs (NR)
6 Linkage (NR)
Description/Instructions
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 bouding rectagle, 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 area, and/or right ascension data, and/or equinox. The mathematical data in this field is also recorded in coded form in field 034 (Coded Cartographic Mathematical Data).

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. AACR2 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.
Editing instructions

Input a period at the end of the field.
Subfields

$a Statement of scale.
Subfield $a contains the entire scale statement including any equivalency statements. Vertical scales or vertical exaggeration statements for relief models or other three-dimensional items are also included in subfield $a.
In records formulated according to ISBD principles, subfield $a includes all data up to and including the semicolon (;) when subfield $a is followed by subfield $b.
255 ## Scale not given.
255 ## Scale [ca. 1:90,000].
255 ## Scale [1:6,336,000]. 1" = 100 miles. Vertical scale [1:192,000]. 1/16" = approx. 1000'.
255 ## Scale not given ; b Conic proj.
$b Statement of projection.
Subfield $b contains the entire projection statement, if applicable. In records formulated according to ISBD principles, subfield $b includes all data following the semicolon (;) and up to but not including the opening parenthesis (() that introduces subfields $c, $d, and/or $e.
255 ## Scale [ca. 1:500,000] ; $b Base fitted to Lambert conformal conic proj. based on standard parallels of 33° and 45°.
255 ## Scale [1:13,835,000]. 1 cm. = 138 km. 1 in. = 218 miles ; $b Chamberlin trimetric proj.
255 ## Scale 1:22,000,000 ; $b Conic proj. $c (E 72°--E 148°/N 13°--N 18°).
$c Statement of coordinates.
Subfield $c contains the statement of coordinates. The coordinates are recorded in the order of westernmost longitude, easternmost longitude, northernmost latitude, and southernmost latitude.
In records formulated according to ISBD principles, subfield $c data are enclosed in parentheses. The two longitude statements and the two latitude statements are each separated by a two hyphens (--). The longitude is separated from the latitude by a slash (/).
255 ## Scale 1:7,500,000 $c (W 125°--W 65°/N 49°--N 25°).
255 ## Scale 1:250,000 $c (E 32°30'--E 34°30'/N 35°30'--N 35°00').
255 ## Scale [ca. 1:10,000] ; $b Gauss proj. $c (W 9°13'52"--W 9°04'47"/N 38°48'35"--N 38°41'29").
$d Statement of zone.
Subfield $d contains the statement of zone for celestial charts.
In records formulated according to ISBD principles, subfield $d data, along with any subfield $e data, are enclosed in parentheses.
255 ## Scales vary $d (Zones +90° to +81° to 63°, -81° to 98° ; $e eq. 1950).
255 ## Scale 88 mm per 1° $d (RA 16 hr./Decl. +30° ; $e eq. 1973.50).
$e Statement of equinox.
Subfield $e contains the statement of equinox or epoch. In records formulated according to ISBD principles, subfield $e data, along with any subfield $c or $d data, are enclosed in parentheses.
255 ## Scale not given $d (RA 0 hr. to 24 hr./Decl. +90° to -90° ; $e eq. 1980).
255 ## Scales vary $e (Eq. 1986.00).
$f Outer G-ring coordinate pairs.
Subfield $f contains coordinate pairs that identify the closed non-intersecting boundary of the area covered.
$g Exclusion G-ring coordinate pairs.
Subfield $g contains coordinate pairs that identify the closed non-intersecting boundary of the area contained within the G-polygon outer ring that is excluded.
$6 Linkage.
For instructions on the use of subfield $6, see Field 880.
Related fields, etc.
034