MARC 21 Format for Bibliographic Data: 007: Electronic Resource (Network Development and MARC Standards Office, Library of Congress)

When field 007/00 contains code c, it contains special coded information about the physical characteristics of an electronic resource.

GUIDELINES FOR APPLYING CONTENT DESIGNATORS

■ CHARACTER POSITIONS

00 - Category of material

c - Electronic resource

One-character alphabetic code that indicates the category of material to which the item belongs is electronic resource (e.g, programs, data files, image files, digitized audio and video tapes, etc.), which usually consist of digitized machine-readable data, program code, etc. intended to be accessed, processed, or executed by a computer. A fill character (|) is not allowed in this position.

01 - Specific material designation

Special class of material (usually the class of physical object) to which an item belongs (e.g., a magnetic disk).

a - Tape cartridge

Removable module containing secondary storage medium such as magnetic tape or magnetic disks.

b - Chip cartridge

Removable module containing a miniaturized electronic circuit, mass-produced on a tiny chip or wafer of silicon, designed to provide additional processing or memory capacity to a computer.

c - Computer optical disc cartridge

Removable module containing one or more nonmagnetic discs used to store digital information.

d - Computer disc, type unspecified

A disc whose type is not specified.

e - Computer disc cartridge, type unspecified

A disc cartridge whose type is not specified.

f - Tape cassette

Removable module, somewhat like an audio cassette, that contains magnetic tape that can be written on and read from by a tape drive.

h - Tape reel

Removable spool containing magnetic tape that can be written to and read from by a tape drive.

j - Magnetic disk

Digital information storage medium usually consisting of a thin Mylar disk coated with a magnetic material that permits the recording of data. Magnetic disks come in various sizes. They are also known as floppy disks, stiffy disks, computer diskettes, or floppy diskettes.

k - Computer card

m - Magneto-optical disc

Erasable or semi-erasable storage medium, similar to a CD-ROM disc, capable of storing data at a very high density. The disc is written to and read from using a laser beam used to heat the recording surface to a point at which regions of the surface of the disk become magnetically aligned to store bits of data.

o - Optical disc

Medium that uses a series of laser-burned micron-sized holes (pits) on a special recording surface to store data. Recorded data is read optically. These discs are usually a read-only medium. Commonly found computer optical disc formats include: CD-A, CD-I, CD-R, CD-ROM, CD-ROM-XA, DVD-ROM and Photo CD.

r - Remote

Electronic resource that is accessed, processed, executed, etc. remotely. In this case the electronic resource is used via input/output devices connected electronically to a computer. Frequently this involves connection through a computer network. The specific material designation of the remotely accessed physical item (e.g., a CD-ROM accessed remotely through a network) is not specified when code r is used in 007/01.

u - Unspecified

Special material designation for the electronic resource is not specified, e.g., it may be an electronic resource that changes its medium over time.

z - Other

None of the other codes is appropriate.

| - No attempt to code

02 - Undefined

Contains a blank (#) or a fill character (|).

03 - Color

Whether the item is one color or multicolored.

a - One color

Images are intended to be produced in a single color other than black (e.g. pink and white, brown and white). If the images are black with white use code b.

b - Black-and-white

Images are intended to be produced in black and white. ASCII files, which do not include color, are coded as b.

c - Multicolored

Image is printed or executed in more than one color. Code c is used for color photographic processes.

g - Gray scale

Image is produced with degrees of dark to light from black to gray to white.

m - Mixed

Work or collection is a combination of one color, black-and-white, multicolored, hand colored, and/or other images.

n - Not applicable

Color is not applicable to the electronic resource, usually because it does not involve anything visual (e.g., digitally encoded audio data).

u - Unknown

Color characteristics of an item are not known.

z - Other

None of the other codes is appropriate.

| - No attempt to code

04 - Dimensions

Dimensions of the medium used to encode the electronic resource.

Only the most common dimensions are indicated. In many cases the dimensions apply to the container in which a magnetic or optical medium is encased. The field 007/04 code corresponding to the dimensions given in the description of the item are used. If no code exactly matches the dimensions of the medium (or container), code z is used.

a - 3 1/2 in.

Diameter of the medium is 3 1/2 inches. It usually refers to the diameter of a magnetic disk.

e - 12 in.

Diameter of the medium is 12 inches. It usually refers to optical or magneto-optical disc.

g - 4 3/4 in. or 12 cm.

Diameter of the medium is 4 3/4 inches (or 12 cm.) It usually refers to optical or magneto-optical disc.

i - 1 1/8 x 2 3/8 in.

Dimensions of the container used for the medium are 1 1/8 x 2 3/8 inches. It usually refers to cartridges.

j - 3 7/8 x 2 1/2 in.

Dimensions of the container used for the medium are 3 7/8 x 2 1/2 inches. It usually refers to cartridges.

n - Not applicable

Physical dimensions are not applicable to the electronic resource. This code is appropriate for remote electronic resources and electronic resources whose specific medium varies (coded u in byte 01).

o - 5 1/4 in.

Diameter of the medium is 5 1/4 inches. It usually refers to the dimensions of a magnetic disk.

u - Unknown

Dimensions of the medium used for the electronic resource are not known.

v - 8 in.

Diameter of the medium is 8 inches. It usually refers to the diameter of a magnetic disk or optical disc.

z - Other

None of the other codes is appropriate.

| - No attempt to code

05 - Sound

Whether the production of sound is an integral part of an electronic resource.

# - No sound (silent)

Not intended to produce sound.

a - Sound

Includes digitally encoded sound or is intended to produce sound.

u - Unknown

Presence or absence of sound or the ability of an electronic resource to produce sound is not known.

| - No attempt to code

06-08 - Image bit depth

Exact bit depth of the scanned image(s) that comprise the electronic resource, or a three-character alphabetic code which indicates that the exact bit depth cannot be recorded. Since only exact bit depth is useful, coding should not include missing digits represented by hyphens (-).

Bit depth is determined by the number of bits used to define each pixel representing the image.

001-999 - Exact bit depth

Image bit depth should be recorded if a single numeric value applies to all files, e.g., all files were scanned in 24-bit color. The numeric value of the image bit depth, using three digits, is right justified with leading zeros (e.g., 001, 024).

mmm - Multiple

Comprised of images that have been scanned and captured at more than one bit depth, such as a volume with text and color images where the text has been scanned as bitonal (1-bit) images and the color plates have been scanned and captured using 24-bit color.

nnn - Not applicable

Bit-depth is not applicable to this electronic resource because there are no images.

--- - Unknown

Bit depth level of the image(s) comprising the electronic resource are not known.

||| - No attempt to code

09 - File formats

Whether the file(s) which comprise the electronic resource are of the same format or type for digitally reformatted materials.

Values do not indicate specific types of file formats, which may be contained in variable fields in the record. The information indicates the number of file formats used.

a - One file format

File(s) which comprise(s)the electronic resource are of the same format or type (e.g., all .jpg; all .tif; all .txt; all .wav; all .mpg; etc.).

m - Multiple file formats

Files which comprise the electronic resource are of at least 2 different formats (e.g., .jpg and .tif; .tif and .txt; .sgml and .wav; etc.).

u - Unknown

Format(s) of the file(s) which comprise(s) the electronic resource are not known.

| - No attempt to code

10 - Quality assurance target(s)

Whether quality assurance targets have been included appropriately at the time of reformatting/creation of the electronic resource.

Targets are standard reference points which can be interpreted by a human or machine and used to measure resolution, color, faithfulness of representation to the original, etc.

a - Absent

Quality assurance targets were not included at the time of reformatting and/or are not present in the electronic resource.

n - Not applicable

Inclusion of quality assurance targets is not applicable to this electronic resource.

p - Present

One or more quality assurance targets were appropriately included at the time of reformatting and are present in the electronic resource. Commonly found quality control targets for scanning include the Kodak Q13 or Q14 Color Separation Guide and Gray Scale; Kodak Q60 Color Input Target; AIIM Scanning Test Chart #2; and the RIT Alphanumeric Resolution Test Object. Commonly found quality assurance targets for re-recording/transfer of audio files include reference and azimuth tones.

u - Unknown

Presence of quality assurance targets in the electronic resource is not known.

| - No attempt to code

11 - Antecedent/Source

Information about the source of a digital file important to the creation, use and management of digitally reformatted materials.

a - File reproduced from original

Content (image, audio, or video) comprising the electronic resource has been created by digitization of the original item. Common examples of original objects include: printed or manuscript texts and/or images that are made on paper or on vellum; photographic prints (and in some instances photographic negatives, depending on creator's intent); analog audio formats; and video formats. This value does not pertain to microform even if microform is the original.

b - File reproduced from microform

Content comprising the electronic resource has been created by scanning from microform (16mm microfilm, 35mm microfilm, 105mm microfiche, microcard, micro-opaque, etc.).

c - File reproduced from an electronic resource

Electronic resource has been created or copied from an existing electronic resource (e.g., to generate new copies or derivative copies with lower resolution or smaller file size; to process an existing file with Optical Character Recognition - OCR - software; etc.).

d - File reproduced from an intermediate (not microform)

Content comprising the electronic resource has been created by reformatting/digitizing from an intermediate other than microform. Common examples of non-microfom intermediates for visual and textual materials are: photocopies, 35 mm film, transparencies, slides, 2nd generation video tape, etc. A common example of an intermediate for audio materials is 2nd generation analog tapes.

m - Mixed

Images comprising the electronic resource have been created from mixed sources (portions scanned from original item, portions scanned from microfilm, etc.).

n - Not applicable

Antecedent or source are not applicable to this electronic resource. This code is appropriate for electronic resources other than those created during a reformatting process.

u - Unknown

Antecedent or source of this reformatted electronic resource is not known.

| - No attempt to code

12 - Level of compression

Kind of compression the electronic resource has been subjected to.

Used to judge the fidelity of the file to the original.

a - Uncompressed

Electronic resource has not been compressed through the use of any compression technique.

b - Lossless

Electronic resource has been compressed and the compression type used is "lossless." Lossless compression will allow an electronic resource to be compressed and decompressed with absolute fidelity each time. To be considered lossless, no informational loss may occur during this process. An example of a lossless compression scheme would be TIFF Group 4 compression employed on bitonal image files.

d - Lossy

Electronic resource has been compressed and the compression type used is "lossy." Lossy compression schemes employ techniques which average or discard some of the encoded digital information. When the file is decompressed, it will not be an exact replica of the original file. Examples of lossy compression schemes include JPEG, and Kodak ImagePac (Photo CD), AC-3 (Dolby Digital) and MPEG.

m - Mixed

Mixture of techniques has been used to compress various parts of the electronic resource.

u - Unknown

Compression techniques are not known.

| - No attempt to code

13 - Reformatting Quality

Reformatting quality of the electronic resource; an overall assessment of the physical quality of the electronic resource in relation to its intended use. It can be used to judge the level of quality of a file, and an institution's commitment to maintain its availability over time.

a - Access

Electronic resource is of a quality that will support current, electronic access to the original item (reference use), but is not sufficient to serve as a preservation copy.

Examples of electronic resources created for access purposes may include images created for a temporary, online exhibition (possibly to mirror an in-house installation); compressed, lower resolution versions of higher-quality master files that allow for easier transmission and access over the Internet; video converted to MPEG-2 for Internet access; photos which have been scanned at lower resolutions to create an online browsing tool for a collection; or articles scanned as a part of an E-Reserve collection which will be discarded in accordance with previous copyright agreements which specify a time limit on the retention of the electronic resource.

n - Not applicable

Reformatting quality is not applicable to the electronic resource.

p - Preservation

Electronic resource was created via reformatting to help preserve the original item.

Capture and storage techniques associated with preservation files ensure high-quality, long-term electronic resources that warrant long-term protection.

r - Replacement

Electronic resource is of very high quality and, when printed out, viewed on screen or played via a listening device could serve as a replacement should the original be lost, damaged, or destroyed.

u - Unknown

Reformatting quality of the electronic resource is not known.

| - No attempt to code

■ EXAMPLES


007/00-13	cu#gn#008apabp [Item is a digitized version of an original, reformatted for preservation purposes (007/00, 11, 13). The electronic resource is comprised of grayscale TIFF images only (no sound) which were scanned at a bit depth of 8 bits per pixel, including quality control targets and is compressed using lossless compression (03, 05, 06-08, 09, 10, 12). Because this file was created for preservation purposes, the medium on which the file is stored will vary as it is refreshed and migrated to new systems to remain accessible (01, 04).]


007/00-13	cu#gn#008apabr [Item is a digitized version of an original, reformatted (and replaced) during preservation (007/00, 11, 13). The electronic resource is comprised of grayscale TIFF images only (no sound) which were scanned at a bit depth of 8 bits per pixel, including quality control targets and is compressed using lossless compression (03, 05, 06-08, 09, 10, 12). Because this file was created to replace the original volumes, the medium on which the file is stored will vary as it is refreshed and migrated to new systems to remain accessible (01, 04).]

INPUT CONVENTIONS

CONTENT DESIGNATOR HISTORY

In 2002, the Computer File 007 field was renamed "Electronic Resource."

007/00 - Category of material

c - Computer file

007/01 - Specific material designation

d - Computer disc, type unspecified [NEW, 2009]

e - Computer disc cartridge, type unspecified [NEW, 2009]

k - Computer card [NEW, 2009]

007/02 - Original versus reproduction aspect [OBSOLETE, 1997] [USMARC only]

Defined codes were: f (Facsimile), o (Original), r (Reproduction), and u (Unknown).

007/03 - Color

b - Black-and-white [NEW, 1999]

h - Hand coloured [OBSOLETE, 1997] [CAN/MARC only]

007/06-08 - Image bit depth [NEW, 1999]

007/09 - File formats [NEW, 1999]

007/10 - Quality assurance targets [NEW, 1999]

007/11 - Antecedent/source [NEW, 1999]

c - File produced from a computer file

In 2002, code c was renamed "File produced from an electronic resource."

007/12 - Level of compression [NEW, 1999]

007/13 - Reformatting quality [NEW, 1999]

007 - Electronic Resource (R)

FIELD DEFINITION AND SCOPE

GUIDELINES FOR APPLYING CONTENT DESIGNATORS

■ CHARACTER POSITIONS

■ EXAMPLES

INPUT CONVENTIONS

CONTENT DESIGNATOR HISTORY


007/00-05	cj#ca# [Item is a computer program on 3 1/2 inch diskette (007/00, 01, and 04), which supports a color (03) video interface but no sound (05).]


007/00-05	co#cga [Item is interactive software and data on a 4 3/4 inch optical disc (CD-ROM) (007/00, 01, and 04) intended to be viewed in color (03) with sound (05).]


007/00-05	cr#bn# [Item is a textual electronic journal available remotely (007/01), formatted as ASCII text (007/03).]


007/00-13	co#ngannnaadda [Item is an access version of an audio file which had been digitally reformatted from the 2nd generation analog tape and is stored on a CD (007/00, 01, 04, 05, 09, 11, 13). Quality assurance target tones are not present on this mpeg-compressed access copy (10, 12). Because it is not an image or video file, color and bit depth aspects are not applicable (03, 06-08).]