There are several versions of MARC in use in the world, the most predominant being MARC 21, created in 1999 as a result of the harmonization of U.S. and Canadian MARC formats, and UNIMARC, widely used in Europe. The MARC 21 family of standards now includes formats for authority records, holdings records, classification schedules, and community information, in addition to formats for the bibliographic record.

Widespread use of the MARC standard has helped libraries acquire predictable and reliable cataloging data, make use of commercially available library automation systems, share bibliographic resources, avoid duplication of effort, and ensure that bibliographic data will be compatible when one automation system is replaced by another.

The MARC record has three components:

Record structure - an implementation of national and international standards, such as the Information Interchange Format ANSI Z39.2 and Format for Information Exchange ISO 2709

Content designation - codes and conventions that explicitly identify and characterize the data elements within a record to facilitate the manipulation of data, defined in the MARC 21 Format for Bibliographic Data and other MARC 21 formats maintained by the Library of Congress

Data Content - defined by external standards such as AACR2, Library of Congress Subject Headings (LCSH), etc.

The MARC record is divided into fields, each containing one or more related elements of bibliographic description. A field is identified by a three-digit tag designating the nature of its content. Tags are organized as follows in hundreds, indicating a group of tags, with XX in the range of 00-99:

0XX fields - Control information, numbers, codes

1XX fields - Main entry

2XX fields - Titles, edition, imprint

3XX fields - Physical description, etc.

4XX fields - Series statements (as shown in item)

5XX fields - Notes

6XX fields - Subject added entries

7XX fields - Added entries other than subject or series

8XX fields - Series added entries (other authoritative forms)

Click here to see an example of a MARC record and here to connect to the MARC Standards homepage maintained by the Network Development and MARC Standards Office of the Library of Congress. See also: Avram, Henriette D.; MARCese; MARCIVE; MARCXML; and USMARC.

Also refers to a rectangular slotted container designed to hold a sequence of slides, queued for use in a slide projector. Compare with carousel.

In computing, a display utility designed to enlarge an area of a computer screen, used by the visually impaired, graphic artists, Web designers, etc. Most screen magnifiers are Windows compliant and can be resized (sometimes with an adjustable zoom factor) and positioned anywhere on the screen. Some allow for replacement of problem colors and even have audio read capability (see this example). Simple magnifiers are available as freeware (see this example).

In Dewey Decimal Classification (DDC), the 10 main classes are indicated by the arabic numerals 0-9 in the first digit of the notation:

See also: division and section.

Also refers to an agreement with an outside company to clean and maintain a library facility on a regular basis in exchange for payment of a monthly or annual fee. Some libraries and library systems hire their own maintenance personnel or use the services provided by the parent organization.

Also refers to a list of the contents of a book in the order in which they are to be bound, provided by the publisher to the binder to ensure that any plates or other additions not printed with the text are included in correct sequence.

Also refers to a book or pamphlet containing practical instructions, rules, or steps for performing a task or operation, assembling a manufactured object, or using a system or piece of equipment (example: Manual of Archival Description published by Gower). Used synonymously with handbook. See also: style manual.

Also, any operation or procedure done by hand rather than by machine, such as the physical processing of a book or other bibliographic item done in a library to prepare the item for circulation or other use.

The Schøyen Collection is a large private manuscript collection (Oslo and London). Illuminated manuscripts can be seen in the online exhibitions Leaves of Gold (Philadelphia area museums and libraries), Treasures of a Lost Art (Cleveland Art Museum), and the CORSAIR database, courtesy of the Morgan Library. See also the Medieval Manuscript Manual (Central European University, Budapest) and The Making of a Medieval Book (Getty Museum). Abbreviated ms. and mss. in the plural. See also: manuscript book, manuscript map, and Manuscript Society, The.

Maps are categorized by the type of content and method of presentation. See also: ancillary map, artistic map, base map, bathymetric map, cadastral map, cartogram, chart, choropleth map, city map, cloth map, compiled map, computer-generated map, contour map, decorated map, dynamic map, facsimile map, geologic map, gravity map, historical map, hydrologic map, index map, inset map, interactive map, isoline map, landscape map, location map, main map, manuscript map, mappa mundi, mental map, multimedia map, old map, outline map, photomap, pictorial map, planimetric map, political map, rare map, reconnaissance map, relief map, road map, schematic map, scroll map, sketch map, slope map, strip map, tectonic map, thematic map, topographic map, trail map, translucent map, wall map, war map, and world map.

Drawn on a single large sheet of parchment, the Hereford Mappa Mundi, on public exhibit in Hereford Cathedral in England, is the largest and most elaborate surviving pre-15th-century world map (see Mappa Mundi: The Hereford World Map by P.D.A. Harvey, British Library, 1996). Click here to see a digital image of the map and to learn more about it.

Originally developed in the East (Japanese examples survive from the 9th century), the technique was used in Persian book production as early as the 16th century. Introduced into Europe in the late 16th century, marbling was particularly popular during the Victorian period in deluxe editions (see this example of marbled endpapers in an early edition). As a less expensive alternative, endpapers are sometimes printed in a pattern that resembles hand-marbling. To see historical examples of marbling used in bookbinding, try a search on the keyword "marbled paper" in the British Library's Database of Bookbindings.

In cartography, the area of a map or chart lying outside the border, usually blank but sometimes bearing marginal data and occasionally one or more ancillary maps. Click here to see the neat line, border, and narrow margin on a map of Niagara Falls printed in 1894 (Perry-Castañeda Library) and here to see the wide margin on a USGS topographic map of Mount Shasta, California.

Also refers to an artist, writer, composer, or craftsman who consistently creates works of the highest quality (example: Mozart). In medieval manuscript illustration, an artist whose work was so exceptional that it became widely known and appreciated in Europe and influenced the direction of illumination, for example, the Boucicaut Master whose Paris workshop produced highly innovative miniatures in the early 15th century (Getty Museum). Some masters are known by name (examples: Jean Bourdichon and Simon Bening); others are identified only by their style (examples: Bute Master and Spitz Master). See also: masterpiece.

Also refers to the round sticker affixed to the front cover or dust jacket of an award-winning book or incorporated into the cover design, sometimes a representation, in metallic ink or paper, of the actual medal received, as in the John Newbery Medal for juvenile fiction.

Also refers collectively to all the channels through which information is broadcast, including radio, television, cable, and the Internet. The mass media disseminate public information to the widest possible audience (and some would argue to the lowest common denominator) with a close eye on the profits to be made from advertising, as in the case of major commercial television networks. Although the producers of this one-way flow of information may use polling to reveal the characteristics of their listeners or viewers, the individuals who receive their message remain largely anonymous. The news media (newspapers, newsmagazines, news broadcasts, news Web sites, etc.) specialize in providing the latest information about current events, with or without commentary, usually without intending to entertain. Directory information on print and broadcast media is available in the Gale Directory of Publications and Broadcast Media, an annual reference serial available in most academic and large public libraries. Singular: medium. See also: media literacy and public television.

In printing, a typeface of intermediate weight, as distinct from lightface or boldface. Medium type is standard for printed text. See also: mediumistic writing.

Also, a written or printed list of the dishes and beverages that may be ordered at a restaurant or other eating establishment or that are to be served at a banquet or other occasion, often divided into categories to facilitate selection (see this example). Menus are considered a form of ephemera and are collected by libraries and archives mainly for their historical value. Click here to see a collection of menus of restaurants in the Puget Sound area in the University of Washington Digital Collections. Synonymous with bill of fare.

Metaphor has been used as a literary device since the earliest works of recorded literature ("rosy-fingered dawn") to enable imaginative writers to expand the literal meaning(s) of word and phrase. When the elements compared are so dissimilar as to be incongruous, the resulting mixed metaphor ("mixaphor") can be amusing ("rusty lips"). A dead metaphor has become so commonplace as to have lost its force ("time marches on"). The history and grammar of metaphor is studied in the discipline of linguistics. Metaphors are sometimes collected and indexed, usually thematically (see the Metaphors Dictionary edited by Elyse Sommer and Dorrie Weiss).

In most academic libraries, the ERIC document collection is available on microfiche, filed by the six-digit ED number assigned to each document. Newspaper and periodical back files and government documents may also be available on microfiche, usually stored in specially designed metal filing cabinets. The sheets of film may be enclosed in microfiche envelopes to prevent abrasion. The Library of Congress provides Microfilm/Microfiche Photoduplication as a fee-based service. Click here to learn more about microfiche, courtesy of Wikipedia. Abbreviated fiche. Compare with microfilm. See also: superfiche and ultrafiche.

In many libraries, newspaper and periodical back files are routinely converted to microfilm to save space. Microfilm is the most common form of substitution. Microform reader-printer machines are available in libraries with microfilm holdings for viewing and making hard copies. User resistance can be mitigated by keeping equipment in good repair and by providing point-of-use assistance. The Library of Congress provides Microfilm/Microfiche Photoduplication as a fee-based service. Click here to learn about The History of Microfilm: 1839 to the Present, courtesy of the Southern Regional Library Facility, University of California. Compare with microfiche. See also: master negative, print master, and service copy.

In the case of unpublished manuscripts and maps, a microreproduction is cataloged as an original edition if issued by a commercial publisher (including on demand agencies such as University Microfilms International) or is issued by a non-commercial agency, such as a university photoduplication department, but contains an explicit edition statement relating to the photoreproduction. The statement need not be formally presented and may be on accompanying material. See also: reformat.

Also, a privately funded library devoted to documenting military heritage, for example, the Pritzker Military Library in Chicago, Illinois, which aims to acquire and maintain a collection of materials and develop programs on the role of the citizen soldier in a democracy.

Also refers to a small, separate, minutely detailed drawing, painting, or portrait, usually done on ivory or vellum (see this example from Australia or this selection from The Royal Collection of the UK). See also: Cosway binding.

In printing and reprography, a document conceived on a very small scale or a greatly reduced copy of a document, designed to be read or reproduced with the aid of special optical equipment. See also: miniature book and miniature edition.

Click here to see a set of 18th-century Dutch miniature books in deluxe binding (Koninklijke Bibliotheek). An online exhibition of Miniature Books is provided by the Cushing Memorial Library, Texas A&M University. See also 4000 Years of Miniature Books (Lilly Library, Indiana University). For more information, see the Web site maintained by the Miniature Book Society. See also: miniature edition, miniature library, and necklace book.

Also, a library furnishing designed to be used alone or in combination with other units to create a customized workspace, for example, worktables of various shapes that can be pushed together to form different configurations, depending on the needs of a particular work group. Modern furnishings for office spaces and computer workstations are often modular in design.

Also refers to a picture distortion seen as a wavy image in photography and graphic displays, which arises when different resolutions or frequencies are superimposed (see this example).

In hand papermaking, a wire screen firmly attached to a wooden frame, used as a sieve to catch a uniform layer of liquefied fiber when dipped into a vat of pulp (see this example, courtesy of the Cary Collection, Rochester Institute). The deckle is the edge along which the mat of fiber meets the frame of the mold. Also spelled mould.

Also, to check on a person or process periodically to make sure work is progressing smoothly.

For the purpose of library cataloging, any nonserial publication, complete in one volume or intended to be completed in a finite number of parts issued at regular or irregular intervals, containing a single work or collection of works. Monographs are sometimes published in monographic series and subseries. Compare with book.

Also refers to the remarks of a person who continues to speak without interruption for an extended period of time despite cues from listeners that the conversation is being monopolized (reference librarians interrupt politely).

Between 1902 and 1906, the elder Morgan had an Italian Renaissance-style building constructed adjacent to his residence in New York City to house the collection. In 1928, an Annex was added, and in 1991 the facility doubled in size with the acquisition of the Morgan townhouse and construction of a garden court to connect the various parts. Items from its collections are selectively exhibited in a small museum associated with the Library. Click here to connect to the homepage of the Morgan Library.

One of the most durable leathers used in bookbinding, morocco is strong yet flexible. Old books bound in morocco are often rare and valuable. Click here to see an early 19th-century binding in green straight-grained morocco (Special Collections, Glasgow University Library, S.M. 1114). To see other examples, try a keyword search on the term "morocco" in the British Library's Database of Bookbindings. Compare with calf and pigskin. See also: levant.

Still juggling his artistic endeavors with writing and political activism, Morris founded the Kelmscott Press in 1891 and launched a serious revival of the book arts. Unfortunately, he died in 1896 after having published only 53 books under the Kelmscott imprint, but his influence on the graphic arts and the aesthetics of book production was considerable. The Kelmscott edition of The Works of Geoffrey Chaucer is considered one of the finest books ever issued, and his work inspired a generation of fine presses in Britain and the United States. Click here to learn more about Morris' life, courtesy of the Ransom Center, University of Texas at Austin. A selection of his designs is displayed online by the William Morris Society in the U.S. Click here to see an example of his bookbinding, courtesy of Queen's University Libraries.

The Code included restrictions on the depiction of sex, marriage, abortion, prostitution, religion, crime, suicide, murder, drug addiction, child kidnapping, and profanity. Under the Code, no motion picture could be shown in an MPPDA-affiliated theater without prior approval. It was overturned by the U.S. Supreme Court in 1952 in a decision that brought motion pictures under the protection of the First Amendment. In 1953, United Artists ignored the Code by releasing The Moon Is Blue by Otto Preminger, a film in which sex is frankly discussed (using the words "virgin" and "pregnant"), without the Code's seal of approval. In 1968, the film industry switched to the advisory content ratings system currently in use. Click here and here to learn more about the Code. Synonymous with Hays Code and Breen code.

Also refers to an artifact or specimen placed on a pedestal or inside a case and to a print, photographic image, or document protected by framing, usually against a backing material. Loose specimens and unframed prints and pictures are unmounted. See also: mat.