DATE: May 23, 2003
NAME: Changes to Field 352 (Digital Graphic Representation) in the MARC 21 Bibliographic Format
SOURCE: Anglo-American Cataloguing Committee for Cartographic Materials
SUMMARY: This paper proposes adding subfield $q to field 352 (Digital Graphic Representation) to the MARC 21 Bibliographic Format in order to be able to record the format in which the digital image is stored and making subfield $g obsolete (VPF topology level).
KEYWORDS: Field 352 (BD); Digital Graphic Representation (BD); Format Name (BD)
05/23/03 -- Made available to the MARC 21 community for discussion.
06/21/03 - Results of the MARC Advisory Committee discussion - Approved as amended. Participants noted that communities may use other cataloging codes besides the AACR2 and may thus need to code subfield $g. It will not be made obsolete. LC might also consider ways to accommodate file format information that may be used by all forms of material.
07/23/03 - Results of LC/NLC/BL review - Agreed with the MARBI decisions.
In 1995, field 352 (Digital Graphic Representation) was defined to support the Content Standard for Digital Geospatial Metadata and the work of the Federal Geographic Data Committee. Since that time AACR2 Chapter 3 (Cartographic Materials) has been revised and reissued as part of AACR2 (2002 revision). Rule 3.3A1 was modified to add prescribed punctuation for digital graphic representation data and rules 3.3F and 3.3.F1 were added to provide general instructions for recording the digital graphic representation for cartographic electronic resources. AACR2 rule 3.3F1 calls for the inclusion of the format name used to store the digital image.
|From the Anglo-American Cataloguing Rules ( revised Chapter 3):|
|Precede the object type by a space, colon, space.|
|Enclose each statement on the number of objects in parentheses after the object type.|
|Precede the format name by a space, semicolon, space.|
|3.3F. Digital graphic representation|
|3.3F1. For an electronic resource, if the information is readily available, give the data type (e.g., raster, vector, point), the object type (e.g., point, line, polygon, pixel), the number of objects used to represent spatial information, and the format name (e.g., digital transfer information). More detailed information such as topology level (e.g., VPF) and compression may be given in a note (see 3.7B8).|
|Point : point ; ASCII|
|Raster : pixel (5,000 x 5,000) ; TIFF|
|Vector ; Shape|
|Vector : points, lines and polygons ; E00|
|Vector : network chains|
|Vector : point (13671), string (20171), GT-polygon composed of chains (13672) ; ARC/INFO export|
Format name in the cataloging rules does not use a controlled list, although a fairly complete list does exist in the FGDC Content Standard for Digital Geospatial Metadata, as of 1998 (this is a U.S. standard). This might be a source for the terms, but as new formats come into existence (e.g. MrSID), new terms will evolve. There is no plan to specify use of a controlled list because for the most part the format is related to the extension used and will therefore be somewhat controlled.
2.1.2. Topology level. Since AACR2 now relegates information of the topology level to a note (and not included in Area 3, represented by field 352), subfield $g (VPF topology level) should be made obsolete. The data would be recorded in field 500:
|500 $a Topology level 2.|
When field 352 was approved in 1995, the prescribed punctuation was not yet established. The amended rule 3.3A1defines the punctuation to be used to separate the elements of this field.
Currently in the MARC 21 Bibliographic format, there are several places to record file format information. In field 856 (Electronic Location and Access), subfield $q (Electronic format type) is defined as:
|"An identification of the electronic format type, which is the data representation of the resource, such as text/HTML, ASCII, Postscript file, executable application, or JPEG image. Electronic format type may be taken from enumerated lists such as registered Internet Media Types (MIME types)."|
The format information is relative to the resource at the location specified in subfield $u. Unparsed (and often more general) format information may be included in other parts of the record, including as a qualifier to an ISBN in field 020, in field 300 (Physical description) or in a note in field 500 (General note) or field 538 (Systems details note).
In the future, there may also be a need to record specific format information for electronic books in bibliographic records. There are a number of electronic book file formats that may be available. The ONIX standard, which is used for representing and communicating book industry product information in electronic form, includes an element called "epublication format code". Currently there is no place to map this element to MARC 21, but it may be useful information to record.
It might also be argued that file format information should not be included in a bibliographic record, because it is technical metadata that is likely to change over time. Frequently, institutions record such information in the technical metadata in digital repositories at the item (rather than manifestation) level. Electronic resources may be migrated to different formats as technology changes. Recording such dynamic information in a bibliographic record may not be desirable.
Whether format name should be defined in different places throughout the MARC 21 bibliographic record is a consideration in the definition of this subfield in field 352. In addition, since the cataloging rules are still in a state of flux in terms of file format information for materials other than cartographic, the situation may change in the future. For instance, it has been proposed in the revision of AACR2 Chapter 9 (Electronic resources) that file format information may be specified in field 300 $b (Other physical details). Note that this is only a proposal that has not been approved by all members of the Joint Steering Committee for Revision of Anglo-American Cataloguing Rules.
This option suggests using either field 500 (General note) or 538 (System details note) for format name, with identifying text that would enable locating the data later. This is the current approach in the Library of Congress' Geography and Map Division, where "Format name:" is used preceding the data in field 500. This might be a temporary measure while further changes to AACR2 regarding format information for other forms of material are considered. If field 352 is repeated and there is need to link a note to it, subfield $8 (Field link and sequence number) could be used.
This approach would necessitate a discussion paper or proposal to investigate the possibility of finding a place for file format information for all forms of material. If defined, it could be used for, among others, the cartographic format name and ebook format name.
|4.1 Format name|
|a) Define subfield $q (Format) in field 352 (Digital Graphic Representation) and update the existing examples to illustrate the prescribed punctuation for the field as follows:|
|$q||Format of the digital image (NR)|
|The name of the format in which the digital image is stored.|
|352 ##||$aVector : $bpoint$c(13671) : $bstring$c(20171) : $bGT-polygon composed of chains$c(13672) ; $qARC/INFO export|
|b) Modify the second sentence in the field definition and scope:|
|This information consists of the type of storage technique used, the number of items in the data set, and the format in which the data is stored.|
|Use a note field (500 or 538) for format name.|
|Add a note subfield to field 352 as follows:|
|Contains a note pertaining to the digital graphic representation.|
|352 ##||$aVector : $bpoint$c(13671) : $bstring$c(20171) : $bGT-polygon composed of chains$c(13672) ; $nFormat name: ARC/INFO export.|
|Explore the definition of a new MARC21 element for file format information.|