Field has no indicators or subfield codes; the data elements are positionally
defined.
When field 007/00 contains code h, it contains special coded information about the
physical characteristics of microform material.
00 - Category of material h - Microform One-character alphabetic code that indicates the category of material to which
the item belongs is microform. Microform is a generic term for
any medium, transparent or opaque, bearing microimages. A microimage
is a unit (e.g., a page) of textual, graphic, or computer-generated material
that is contained on aperture cards, microfiche, microfilm, microopaques, or
other microformats and that is too small to be read without magnification.
Microforms may be reproductions of existing textual or graphic materials or
they may be original publications. A fill character (|) is not allowed in this
position.
01 - Specific material designation Special class of microform to which the item belongs. (e.g., a microopaque).
a - Aperture card Card with one or more rectangular opening(s), or aperture(s), specifically
prepared for the mounting or insertion of a piece of photographic film
containing one or more microimage(s). The cards are usually EAM (Electrical
Accounting Machine) punched cards, commonly known as IBM cards, that are
standardized for use in card-handling machines. Such cards contain only one
aperture and most frequently have only one microimage.
b - Microfilm cartridge Consists of a strip of photographic film wound onto a single core (or hub),
housed in a protective container. Microfilm cartridges require reading
equipment (readers and reader-printers) that is specifically adapted for their
use. Normally, the end of the film is left free for threading into such
equipment. Common film lengths, widths, and reduction ratios are the same as
those of microfilm reels.
c - Microfilm cassette Analogous to the sound tape cassette. Consists of a strip of photographic film
wound onto a double core, housed in a protective container. Microfilm cassettes
require reading equipment (readers and reader-printers) that is specifically
adapted for their use. Because they are double-cored, they are not threaded
when used in such readers and reader-printers. Usual film lengths are 100 ft
(approximately 30 m.) or less. Common film width is 16 mm. and usual reduction
ratios are those of microfilm reels and cartridges.
d - Microfilm reel Consists of a strip of photographic film wound onto an unenclosed flanged
holder (or reel). Microfilm reels require manual threading when used in readers
and reader-printers and require equipment that is adapted for their use. Film
lengths are usually 100 ft. (approximately 30 m.) or less. For microimages
produced by filming textual and graphic materials, the most common film widths
are 35 mm. and 16 mm. and reduction ratios commonly range from about 10:1 to
about 20:1. Sixteen millimeter film with effective ratios of either 24:1 or
48:1 is most often used for COM (Computer-Output-Microfilm) microimages.
e - Microfiche Transparent sheet of photographic film containing microimages arranged in a
grid pattern (a two-dimensional array) and having a heading that contains
identifying information in text that is large enough to be read without
magnification. Grid patterns vary with reduction ratios.
Microfiches are grouped in five ranges of reduction ratios: low reduction
(ratios up to and including 15:1), normal reduction (ratios greater than 15:1
up to and including 30:1), high reduction (ratios greater than 30:1 up to and
including 60:1), very high reduction (ratios greater than 60:1 up to and
including 90:1) and ultrahigh reduction (ratios greater than 90:1).
The most common microfiche are made by filming textual or graphic material at a
reduction ratio of approximately 24:1. Such microfiche are 105 mm. high and 148
mm. wide (approximately 4x6 in.) and have a grid pattern that accommodates 98
microimages made from documents that are no more than 11 in. high and 8 1/2 in.
wide. The heading area is the width of one row and is found directly above the
first row of microimages.
The most common COM (Computer-Output-Microfilm) microfiche are made by
recording computer-generated data at an effective reduction ratio of 48:1 on a
105 mm. x 148 mm. sheet of film. Such microfiche have a grid pattern of 15 rows
and 18 columns, comprising 270 microimages. The heading area is the width of
one row and is found directly above the first row of microimages.
Microfiche made at ultrahigh ratios are commonly called ultrafiche. Ratios and
grid patterns have not been standardized for these microfiche and differ
according to application and method for production.
f - Microfiche cassette
g - Microopaque Sheet of opaque material bearing a number of microimages arranged in a
two-dimensional array. Microopaques resemble microfiche. Common dimensions are
3x5 in. and 6x9 in. Common reduction ratios are approximately 24:1 or 20:1.
Microopaques usually have identifying information in text that is large enough
to read without magnification.
u - Unspecified Special material designation for the microform is not specified.
z - Other None of the other codes is appropriate. Some microform types that use code z
include:
- microchip - A sheet of photographic film of very small
dimensions,
- microdot - A minuscule piece of photgraphic film with
ultrahigh reduction ration,
- microform scroll - A roll of unusually wide photographic
film.
Includes microforms such as microchips, microdots, and microform scrolls.
| - No attempt to code
03 - Positive/negative aspect Positive/negative polarity of the microform.
This characteristic is also referred to as the polarity.
a - Positive Lines and characters appear dark against a light background.
Microopaques are always recorded as code a.
b - Negative Lines and characters appear light against a dark background.
m - Mixed polarity Mixture of positive and negative images.
u - Unknown Polarity of the microform is not known. (Some colored negatives may appear to
be positive if the colors of the original are not known.)
| - No attempt to code
04 - Dimensions Dimensions of the microform; does not indicate the dimensions of the
image.
For example, 16 mm. images on 35 mm. microfilm are coded f (35 mm.). Only the most
common dimensions are indicated. Only codes that exactly match the measurement of
the item as given in the physical description should be used. If no code exactly
matches, code z is used.
The width of a microfilm is indicated in millimeters.
The height and width of a microfiche, microopaque, etc. are indicated in inches or
centimeters. The first dimension is the height, the second is the width. The
standard microfiche (105 mm. x 148 mm.) is coded m.
a - 8 mm.
d - 16 mm.
f - 35 mm.
g - 70 mm.
h - 105 mm.
l - 3x5 in. or 8x13 cm.
m - 4x6 in. or 11x15 cm.
o - 6x9 in. or 16x23 cm.
p - 3 1/4 x 7 3/8 in. or 9x19 cm. Height and width of an aperture card in inches or centimeters.
u - Unknown Dimensions are not known.
z - Other None of the other codes is appropriate.
| - No attempt to code
05 - Reduction ratio range Reduction ratio range for a microform. The specific reduction ratio is recorded in
007/06-08 (Reduction ratio).
For microfilm created by other than COM (Computer-Output-Microfilm) processes and
for microopaque microprints, codes a and b are most likely to be used. For COM
microfiche or microfilm, the reduction ratio is actually an expansion ratio and
refers to the ratio of expansion required to produce a legible image. Most COM is
created at 024-048 reduction ratios (codes b and c), though some COM fiche is at
higher ratios (e.g., 072). Codes b-e are used with other types of microforms
(e.g., microfiche, ultrafiche, etc.). The most commonly encountered microfiche are
normal reduction (code b).
The reduction ratio is usually given on the microform itself. If it is not
present, one must know the dimensions of the original item and the size of the
image on the microform in order to code the information needed in 007/05.
a - Low reduction ratio Less than 16:1 ratio (less than 016).
b - Normal reduction Between 16:1 and 30:1 (016-030).
c - High reduction Between 31:1 and 60:1 (031-060).
d - Very high reduction Between 61:1 and 90:1 (061-090).
e - Ultra high reduction Over 90:1 (over 090).
u - Unknown Reduction ratio is not known.
v - Reduction rate varies Not all parts of the microform have the same reduction ratio (e.g., the
contents of two books may be microfilmed onto one piece of film; the type face
on the books may differ, so that one of the books may be filmed at a 14:1 ratio
and the other at a 18:1 ratio).
| - No attempt to code
06-08 - Reduction ratio Number specifying the reduction ratio for a microform, recorded as three digits.
The number is right justified and each unused position contains a zero (e.g., 015,
048). A hyphen is used for any unknown portion of the reduction ratio (e.g., 03-,
1--, or ---).
A code indicating the reduction ratio range is recorded in 007/05.
Generally, the specific reduction ratio is recorded when it is ultra high (code e
in 007/05). If the ratio is not ultra high, recording the specific ratio is less
essential. Three fill character (|||) are used when no attempt has been made to
code this data element.
09 - Color Color of the image for microforms.
b - Black-and-white Image is in black-and-white (usually black-and-transparent).
Includes only one color or hue other than black, for example, blue-and-white
(blue-and-transparent). Always used for microopaques.
c - Multicolored Has more than one color.
m - Mixed Combination of one-color and multicolored images.
u - Unknown Color of the microform is not known.
z - Other None of the other codes is appropriate.
| - No attempt to code
10 - Emulsion on film Type of light-sensitive material on the film.
Proper storage and use of microforms requires identification of the emulsion they
contain.
a - Silver halide Emulsion is a compound of silver and halogens. Silver halide microforms always
appear black-and-white (black-and-transparent).
b - Diazo Emulsion consists of sensitized layers composed of diazonium salts that react
with couplers to form dye images. The color of the image is determined by the
composition of the diazonium compound as well as the couplers used in the
process and may be black, violet, or another color.
c - Vesicular Light-sensitive component is suspended in a plastic layer. On exposure, the
component creates optical vesicules (bubbles) in the layers. These bubbles form
the latent image. The latent image becomes visible and fixed by heating the
plastic layer and then allowing it to cool. Vesicular films are commonly blue
or beige in color. They do not appear to have much contrast (very high density)
until projected in a microform reader.
m - Mixed emulsion For example, a microfilm may have slices of film with one type of emulsion and
other slices with another type of emulsion.
n - Not applicable Item does not have emulsion on film.
u - Unknown Emulsion on the film is not known.
z - Other None of the other codes is appropriate.
| - No attempt to code
11 - Generation Generation aspect of a microform.
a - First generation (master) Camera master or COM recorder master.
Used for all master films that are made on archival stock in accordance with
archival productions standards and that are given archival storage under
relevant ISO standards.
b - Printing master Any generation employed mainly for the production of other microforms.
Used for all masters that are not manufactured, produced, and stored in
accordance with archival standards.
c - Service copy Microform made from another microform that is intended primarily for use rather
than for production of other microforms. Always used for microopaques.
m - Mixed generation Made up of a combination of generations of film.
u - Unknown Generation aspect is not known.
| - No attempt to code
12 - Base of film Base of the film.
Safety base film is a comparatively nonflammable film base that meets the standard
requirements for a safety base. On some film, the phrase safety base or a
small equilateral triangle appears on the edge of microforms. Some microfilm
produced overseas has similar notations in foreign languages. Vesicular and diazo
microforms are always a safety base, as are silver halide microforms manufactured
in the United States since approximately 1951. Nitrate film base is a highly
flammable film base that does not meet the requirements for safety base film.
a - Safety base, undetermined Type has not been identified.
c - Safety base, acetate undetermined Acetate safety base film whose exact type cannot be determined, i.e., where it
is unknown if the type is diacetate or triacetate.
d - Safety base, diacetate Cellulose diacetate film base. Introduced before World War I for home movies,
diacetate base was more expensive and unpredictable than nitrate base and so
failed to gain acceptance in professional 35 mm. film production. Diacetate
film base was at times used for microfilming of documents.
i - Nitrate base Cellulose nitrate film. Cellulose nitrate support or base was used in the
manufacture of 35 mm. film (and some 17.5 mm. film) until 1951. Nitrate base
film is no longer manufactured. Nitrate film base was at times used for
microfilming of documents.
m - Mixed base (nitrate and safety) Combination of nitrate base and safety base film. The use of mixed bases,
spliced together, can be found in microforms from the early 1950s.
n - Not applicable Microform on a reflective rather than a transparent base.
Microopaques (which can be termed microcard or microprint) are an example of a
microform not produced on a film base and are coded n.
p - Safety base, polyester Film base is made of a synthetic resin (e.g., estar). During the 1980s, it
became the most widely used base for microfilming of source documents.
r - Safety base, mixed Mixed safety base films are spliced together; no nitrate film.
t - Safety base, triacetate Cellulose triacetate film base. Cellulose triacetate is a high acetal compound
with very low flammability and slow burning characteristics. From 1951,
triacetate has been used for professional as well as for amateur produced
moving image film. It has also been used at times for microfilming of
documents.
u - Unknown Base of film of the microform is not known.
z - Other Bone of the other codes is appropriate.
| - No attempt to code
007/02 - Original versus reproduction aspect [OBSOLETE, 1997] [USMARC only]Defined codes were: f (Facsimile), o (Original), r (Reproduction), and u
(Unknown).
007/12 - Base of film
b - Not safety base [OBSOLETE, 1991]
Code b was made obsolete when 007/12 for microforms was made consistent with the
007/12 (Base of film) for motion pictures and code i (Nitrate base) was defined.