The Basics

What is HyperText/HyperMedia?

What is a "Markup Language"?

HTML and SGML Are Related

• The SGML Web Page (a bibliography of resources), created by Robin Cover, and sponsored by OASIS (Organization for the Advancement of Structured Information Standards).
  [http://www.oasis-open.org/cover/sgml-xml.html]
• SGML information from the World Wide Web Consortium (W3C)
  [http://www.w3.org/MarkUp/SGML/]

XML, XHTML and HTML

Extensible Markup Language (XML) is a subset of SGML. Its goal is to enable generic SGML to be served, received, and processed on the Web in the way that is now possible with HTML. XML has been designed for ease of implementation and for interoperability with both SGML and HTML.

Extensible HyperText Markup Language (XHTML) is a reformulation of HTML 4 as an XML 1.0 application.

Where is all this going? Who knows... but you can follow the standards development process through the World Wide Web Consortium Web Site [http://www.w3.org/].

Standards and Specifications

• HTML 4.01 Reference Specification: W3C Recommendation (12/24/00)
  [http://www.w3.org/TR/html4/]

The Library of Congress maintains a guidelines document for HTML 4.01 usage at:

• Library of Congress Guidelines for HTML 4.01
  [http://www.loc.gov/iug/html40/]

Files and Pages

When you write HTML, you will be creating new files or editing existing files. These files will be created locally (in most cases), then transferred onto the RS7 server. Once they are loaded onto the RS7, they can be referred to using a Uniform Resources Identifier (URI). When those URIs are entered into a Web browser like Netscape or Internet Explorer, the files -- with their embedded HTML -- are displayed as Web pages.

The main Web page for a topic, function, or institution is normally called the Home Page. Web pages are often more than one screen long; however, it is recommended that in most cases

What are URIs?

A Uniform Resource Identifier (URI) is the generic scheme for identifying a resource, most often on the Internet. URI is now the name that the W3C uses to identify addresses used for hypertext links in HTML-coded documents. At this point in time, the URI continues to use the specific format of the Uniform Resrouce Locator (URL); however, in most documentation, URLs are now generically referred to as URIs.

The standard addressing structure used on the World Wide Web continues to be the URL. It is a standard Internet addressing scheme that allows computer programs to transfer information over the Internet using the appropriate protocol/language (e.g., FTP [file transfer protocol], TELNET [telnet protocol], TN3270 [telnet 3270 protocol], HTTP [hypertext transfer protocol], NNTP [network news transfer protocol]).

An absolute URL contains the full addressing scheme: the Protocol Type (HTTP, TELNET, etc.), the Full Server Address (the computer's name) and Port (when required), and the Path to the file or directory on the server.

• Between the Protocol and the Server Name in the URL is a colon and two forward slashes --http://www.loc.gov/
• Between the machine name and the path is one forward slash -- http://www.loc.gov/global/

The use of the final slash in URLs that don't end in a file name is highly recommended because some browsers will misinterpret the URL without the final slash:

The URL for the Library of Congress Home Page is: http://www.loc.gov/

The URL for the Library's Public FTP Site is: ftp://ftp.loc.gov/pub/

The URLs for LOCIS are: telnet://locis.loc.gov/ or tn3270://locis.loc.gov/

For more information on URLs consult A Guide to URLs (via Brown University) [http://netspace.students.brown.edu/users/dwb/url-guide.html] or A Beginners Guide to URLs (via NCSA) [http://archive.ncsa.uiuc.edu/demoweb/].

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