The MARC21 format is a standard for the representation and communication of bibliographic and related information in machine-readable form. A MARC record involves three elements: the record structure, the content designation, and the data content of the record.
The structure of MARC records is an implementation of national and international standards, e.g., Information Interchange Format (ANSI Z39.2) and Format for Information Exchange (ISO 2709).
Content designation, the codes and conventions established to identify explicitly and characterize further the data elements within a record and to support the manipulation of those data, is defined in the MARC21 formats.
The content or data, of most data elements is defined by standards outside the formats, e.g., Anglo-American Cataloguing Rules, Library of Congress Subject Headings, etc.
2) What are the contents of the MARC-856 field?
Field 856 contains the following elements:
First Indicator (Access Method). The first indicator contains information about access method to the resource and has values defined for Email, FTP, Telnet, Dial-up, and HTTP. Access methods without defined values may contain a first indicator value 7 with the method indicated in $2.
Second indicator (Relationship). A second indicator is provided to show the relationship between the information in field 856 and the resource described in the record. This may be used for generation of a display constant.
II) Subfield codes
The most commonly used subfields are as follows:
Subfield $u = HTTP URL
Subfield $2 = Access method when first indicator is 7
Subfield $3 = Data specifying what URL refers to, if applicable
Subfield $z = Public note
3) What is DCMI? How is Dublin Core Metadata different from other cataloguing schemas?
The DCMI, i.e., Dublin Core Metadata Initiative is an organization dedicated to design and development of interoperable and specialized metadata standards for describing resources to enable intelligent resource discovery.
The Dublin Core Metadata Element Set (DCMES) provides a semantic vocabulary for describing the ‘core’ information properties, such as ‘Creator’, ‘Title’, ‘Date’, etc.
Dublin Core metadata is different from other cataloguing schemas like MARC, etc and it is not meant to replace the existing standards for describing resources. It is used to supplement existing methods for searching and indexing Web-based metadata to increase the interoperability among databases
belonging different databases. And also, inspite of the fact that the DCMES is used often to describe Internet resources, it can be used to describe any resource, regardless of whether the corresponding resource is an electronic document or a ‘real’ physical object.
ANSI : American National Standards Institute is an organisation of American industry groups works
with the standards committees of other nations to develop standards to facilitate international trade
Attribute : Used to describe information which is in some sense descriptive of a specific element occurring but not regarded as part of its content.
Attribute Value : The value assigned to a given attribute.
Cataloging record : A bibliographic record (essentially the information on a catalog card), created from following the guidelines in the Anglo-American Cataloging Rules.
DTD : Document Type Definition – The DTD defines the structural rules of a type of document. These rules include a complete list of allowable elements and attributes, special character entities, rules for external files (such as images), as well as the hierarchical structure of all elements. Examples of documents type definitions include TEI, EAD, etc.
Dublin Core Metadata : Dublin Core Metadata Initiative the body responsible Initiative (DCMI) for the ongoing maintenance of Dublin Core. DCMI is currently hosted by the OCLC Online Computer
Library Center, Inc., a not-for-profit international library consortium. The work of DCMI is done by
contributors from many institutions in many countries. DCMI is a consensus-driven organization
organized into working groups to address particular problems and tasks. DCMI working groups are
open to all interested parties. Instructions for joining can be found at the DCMI web site under Working Groups (http://dublincore.org)
Element (Dublin Core) : A discrete unit of data or metadata. Example, Title, Creator, Publisher, Date, etc.
Elements (XML) : The technical term used in XML for a textual unit, viewed as a structural component. For example, title, chapter, section, poem, stanza, etc.
Encoding : A process of transferring text and/or data to a searchable electronic medium and organizing it into specific structural and conceptual elements.
HTML : Hypertext Markup Language is the standard textformatting language for documents on the World Wide Web. HTML text files contain content that is rendered on a computer screen and markup, or tags, that can be used to tell the computer how to format that content. HTML tags can also be used
to encode metadata and to tell the computer how to respond to certain user actions, such as a mouse
click. For more information, see http:// www.w3.org/MarkUp/.
ISO : International Organisation for Standardisation was established in 1947 as a worldwide federation of national standards bodies from some 130 countries.
MARC Cataloguing : The process of recording bibliographic information about an item and then coding that information for the machine. The process of coding cataloged information for machines is called MARC tagging. MARC tagging involves coding the fixed and variable fields, subfield, indicators and tags pertinent to a specific format such as books or maps or serials or computer fields.
Metadata : Information about a publication as opposed to the content of the publication; includes not only bibliographic description but also other relevant information such as its subject, price, conditions of use, etc.
OPAC : Acronym for any Online Public Access Catalog (computer catalog). Often, the O is dropped from OPAC, and computer catalogs are referred to as PACs.
PURL : Persistent Uniform Resource Locator is an approach to the URL permanence problem
proposed by OCLC. A PURL is a public alias for a document. A PURL remains stable, while the
document’s background URL will change as it is managed (e.g., moved) over time. A PURL is
created by a Web administrator who is registered as a PURL ‘owner’ and who maintains a mapping
of the PURL to a current and functioning URL.
Retrospective Conversion : The process libraries use to convert their catalogs from card form to machine-readable form, so that bibliographic records can be stored and retrieved in OPACs.
Tag : A Markup Language encoding feature that describes a discrete component of a document,
such as a tag in HTML and
XML : eXtensible Markup Language is a subset of Standard Generalized Markup Language (SGML), a widely used international text processing standard. XML is being designed to bring the power and flexibility of generic SGML to the Web, while maintaining interoperability with full SGML and HTML. For more information, see http:// www.w3.org/XML/
Source: IGNOU Study Material