Universal Resource Characteristics (URCs)

URCs are related to the issues of URNs and URLs within the grouping of URIs.

Metadata

URCs are metadata. These references discuss the general problem of what constitutes metadata.

IEEE Metadata and Data Management Info Page
Position papers on metadata for IEEE workshop
Other Metadata Information Sources
WAIS through the Web - About Metadata by David Crossley. Presented at the Second International WWW Conference Mosaic and the Web - Chicago, USA (17-20 October, 1994).
Introduction to the Bibliographic-data Ontology in the Library of Ontologies
NSDI MetaData and WWW Mapping Sites references a large number of spatial metadata sites.
EPA Scientific Metadata Standards Project is a good list of metadata resources.

Content

These references define the content and interpretation of metadata elements. They describe efforts to generalize metadata for broad areas. They do not claim to be generally applicable to every type of data.

OCLC/NCSA Metadata Workshop Report - describes the Dublin Core.
TEI Guidelines for Electronic Text Encoding and Interchange. Part of a ten year project to define the structure (in SGML) of scholarly text. Considerable attention has been paid to mapping into and out of existing bibliographic data models.
Susan Hockey's presentation Describing Electronic Texts: The Text Encoding Initiative and SGML at the Library of Congress Seminar on Cataloging Digital Documents
The Documentation of Electronic Texts Using Text Encoding Initiative Headers: An Introduction. Richard Giordano, Library Resources and Technical Services. 38(4) 389-401 1994
Discusses the benefits and possible faults of the TEI header as a basis for electronic text cataloging. A basic introduction to TEI headers
Cataloging Electronic Texts: The University of Virginia Library Experience. Edward Gaynor, Library Resources and Technical Services. 38(4) 403-413
Describes one of the first efforts to integrate electronic document cataloging in a conventional library environment; discusses aspects of mapping between TEI headers and MARC records.
Core Bibliographic Record
A new standard of bibliographic description, positioned between full cataloging minimal level cataloging standards. The goal is to reduce the costs of cataloging without substantially compromising the usefulness of the resulting records. May provide some insights as to a target level of description for electronic resources.
The Core Record: A New Bibliographic Standard. Willy Cromwell, Library Resources and Technical Services. 38(4) 415-424 1994
A background paper on the development of a new cataloging level intended to reduce the costs of cataloging; less extensive than conventional full-level cataloging, more detailed than minimal-level cataloging.
The Semantic Header by Bipin C. Desai, is a portion of each document which should contain information useful in searching for a document based on a number of commonly used criteria. It has many of the characteristics of MARC record but tends more towards MLC (minimum level cataloging) rather than TEI.
Core Elements for the The Government Information Locator Service (GILS). Defines required and optional metadata elements for a locator record. Maps these elements to MARC record tags.
Content Standards for Digital Geospatial Metadata. (or an alternate format of this document). This standard specifies the information content of metadata for a set of digital geospatial data. Approved by The Federal Geographic Data Committee. (See also USGS Node of National Geospatial Data Clearinghouse .)
An example of the use of this standard is Digital Geospatial Metadata Standards for Geodetic Data
Metadata References for spatial data, by Doug Nebert of the USGS.
Geospatial Data/Metadata Information at U.S. Army Corps of Engineers
NASA's Directory Interchange Format (DIF) is a format and a content standard.
Scientific and Technical Attribute Set is an open public definition of Scientific and Technical Data Elements, being developed to help support interoperable search and retrieval of Scientific and Technical Databases.
OCLC/NCSA Metadata Workshop is intended to develop a content-based metadata standard
OCLC/NCSA Metadata Workshop: Final Report
Mapping the Dublin Core Metadata Elements to USMARC

This paper reviews the discussions held at the OCLC/NCSA Metadata Workshop in Dublin, Ohio in March about core data elements for discovery and retrieval of Internet resources ("metadata") by a diverse group of Internet users. The data elements as defined by the participants at the Workshop are listed with possible equivalents in USMARC. Problems in mapping are reviewed and options for resolutions are suggested.

A Brief Citation Guide for Internet Sources in History and the Humanities

Format/syntax

These references are concerned with the format for data/metadata.

The Warwick Framework A Container Architecture for Aggregating Sets of Metadata
Proposed URC external Representation by Ron Daniel
SGML is being suggested as a format for complex meta data.
Other SGML-related pages:
- SGML Open Home Page
- SGML Web Page, an extensive compendium of SGML resources, including overviews, FAQs, FTP sites, bibliographies, software, applications, etc.
- comp.text.sgml, an SGML news group.
- ISO/IEC DIS 10179.2 Document Style Semantics and Specification Language (DSSSL) by James Clark.
IAFA - Internet Anonymous FTP Archive templates. Files with indexing information that can be used to describe the contents and services provided by such archives. Automatic indexing tools can gather and index this information.
RFC822 - A field:value format for internet text messages used by mail systems.
RFC1357 - A field::value format for E-mailing bibliographic records, which also specifies content (required and optional fields).
Summary Object Interchange Format (SOIF) used by The Harvest Information Discovery and Access System
PRDM (Partial Redundant Distributed Meta-language), a Lisp-like language for expressing meta info, used in An Architecture for Managing Distributed Meta Information
Source Description Structures are used by a client of the WAIS system to contact a database on a server. The syntax is Lisp-like.
The USMARC Formats: Background and Principles.
The USMARC formats are communication formats, primarily designed to provide specifications for the exchange of bibliographic and related information between systems. They are widely used in a variety of exchange and processing environments. As communication formats, they do not mandate internal storage or display formats to be used by individual systems.
Application Profile for the Government Information Locator Service (GILS) (also in postscript). GILS servers are required to support the following three record syntaxes:
- USMARC -- an implementation of ANSI/NISO Z39.2 and maintained by the Library of Congress
- Generic Record Syntax (GRS-1) -- defined in Z39.50
- Simple Unstructured Text Record Syntax (SUTRS) -- defined in Z39.50.
ASN.1 Abstract Syntax Notation One (on Philipp Hoschka's home page).
- Language Specification (X.208) (in postscript)
- Specification of Basic Encoding Rules for ASN.1 (X.209) (in postscript)
- A Layman's Guide to a Subset of ASN.1, BER, and DER (in postscript) by Burton S. Kaliski, Jr., RSA Data Security, Inc.
NASA's Directory Interchange Format (DIF) is a metadata format and content standard that allows aggregated elements. In use in NASA's Global Change Master Directory (that can be searched) and in NOAA's Data Set Catalog

National Space Science Data Center
Master Directory
4400 Forbes Boulevard
Lanham, Maryland 20706
Bibliographic Formats and Standards is a guide to machine-readable cataloging records in the OCLC Online Union Catalog.

Meta Content Form (MCF) has as its goal to provide an adequate language for representing a wide range of information about content. The content targeted includes web pages, gopher and ftp files, desktop files, email and structured (i.e., relational and object oriented) databases, etc. The corresponding meta-content includes indices such as Yahoo!, gopher and ftp directory structures, email headers, data dictionaries, etc.

Mapping Between Metadata

Mappings between formats and between schemes will ultimately be required no matter how much agreement we achieve within and between domains. We will never get total agreement, and even if we were to get close, things change so we will have to map from the old to the new.

Mapping between metadata formats
KQML (Knowledge Query and Manipulation Language)
Knowledge Interchange Format (KIF) is a computer-oriented language for the interchange of knowledge among disparate programs. It has declarative semantics (i.e. the meaning of expressions in the representation can be understood without appeal to an interpreter for manipulating those expressions); it is logically comprehensive (i.e. it provides for the expression of arbitrary sentences in the first-order predicate calculus); it provides for the representation of knowledge about knowledge.

URC Internet Draft Documents

draft-ietf-uri-urc-req-00.txt URC Scenarios and Requirements
draft-ietf-uri-urc-spec-00.txt Encoding and Use of Uniform Resource Characteristics
(There's much more)

URC Services

(Old!)

URC Service Usage Scenarios, by Ron Daniel
Global Distributed Directory Service for the World Wide Web. A proposal for a URC service by Ron Daniel.