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diff --git a/htdocs/docs/sgml.html b/htdocs/docs/sgml.html new file mode 100755 index 0000000..564064f --- /dev/null +++ b/htdocs/docs/sgml.html @@ -0,0 +1,130 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> + + <head> + <title>W3C HTML Validator SGML Intro</title> + <link rev="made" href="mailto:gerald@w3.org" /> + <link rel="stylesheet" type="text/css" href="/base.css" /> + <meta name="keywords" content="HTML, Hypertext Markup Language, Validation, W3C HTML Validation Service" /> + <meta name="description" content="W3C's easy-to-use HTML validation service, based on an SGML parser." /> + <meta name="revision" content="$Id: sgml.html,v 1.1 2001-02-23 09:06:49 link Exp $" /> + <meta name="modified" content="$Date: 2001-02-23 09:06:49 $" /> + </head> + + <body bgcolor="#FFFFFF" text="#000000" link="#0000ee" vlink="#551a8b"> + <h1><a href="http://www.w3.org/"><img align="left" + src="http://www.w3.org/Icons/WWW/w3c_home" height="48" border="0" + alt="W3C" /></a> HTML Validator SGML Intro</h1> + <p align="right" class="navbar"> + <a href="about.html">About this service</a> | + <a href="whatsnew.html">What's new</a> | + <a href="source/">Source code</a> | + <a href="feedback.html">Feedback</a><br clear="right"/> + <a href="file-upload.html">Upload files</a> | + <a href="http://lists.w3.org/Archives/Public/www-validator/">www-validator archives</a> | + <a href="http://jigsaw.w3.org/css-validator/">CSS validator</a> | + <a href="checklink">Link checker</a><br clear="right"/> + <a href="http://www.w3.org/People/Raggett/tidy/">HTML Tidy</a> | + <a href="http://www.w3.org/MarkUp/">HTML home</a> | + <a href="http://www.w3.org/TR/html401/">HTML 4.01</a> | + <a href="http://www.w3.org/TR/xhtml1/">XHTML 1.0</a> + <br clear="all" /> + </p> + + <div> + <h2 id="sgml">What is SGML?</h2> + <p> + SGML stands for Standard Generalized Markup Language. This is + actually a slight misnomer, since SGML is actually a + <em>meta-language</em> — that is, a language for writing markup + languages. HTML is a markup language written in SGML — an "SGML + application", to use the terminology. + </p> + <p> + You don't actually have to know much about SGML to use The Validator + successfully. If you're interested, though, I recommend TEI's + <a href="http://etext.virginia.edu/tei-tocs1.html">"A Gentle + Introduction to SGML"</a> as a good starting point. An additional SGML + resource can be found on + <a href="http://www.oasis-open.org/cover/sgml-xml.html">SIL's SGML + Web Page</a>. + </p> + </div> + + <div> + <h2 id="dtd">What is a DTD?</h2> + <p> + For our purposes, a DTD, or Document Type Definition, is simply a file + that defines the syntax of a <a href="#sgml">SGML</a>-based language. + The DTD's for + <a href="http://w3.org/MarkUp/html-spec/">HTML 2.0</a> + and <a href="http://w3.org/TR/REC-html32">HTML 3.2</a> + were written by the HTML Working Group of the + <a href="http://www.ietf.org/"><abbr title="Internet Engineering Task Force">IETF</abbr></a>, + in collaboration with the <a href="http://w3.org"><abbr title="World Wide Web Consortium">W3C</abbr></a>. + From <a href="http://w3.org/TR/html4">HTML 4.0</a> on (this includes + <a href="http://w3.org/TR/xhtml1">XHTML</a>), the standards (both + prose and DTDs) have been written by the + <a href="http://w3.org"><abbr title="World Wide Web Consortium">W3C</abbr></a>. + </p> + </div> + + <div> + <h2 id="doctype">What is this <code>DOCTYPE</code> thing The Validator + keeps pestering me for?</h2> + + <p> + A <code>DOCTYPE</code> is a <a href="#sgml">SGML</a> document type + declaration. Its purpose is to tell an SGML parser what + <a href="#dtd">DTD</a> it should use to parse the document. It appears + as the first line of the document, and has the form: + <code><!DOCTYPE html PUBLIC "quoted string"></code> + </p> + <p> + The quoted string is called a <dfn>public identifier</dfn>; it refers + to the desired DTD by a "well-known" name, usually defined by an + associated standard. + </p> + <p> + Most Web browsers don't actually use an SGML parser (in fact, none + that I'm aware of do), and so they don't need a <code>DOCTYPE</code> + declaration, and will ignore it if present. The Validator, however, + does use an SGML parser, and therefore needs a <code>DOCTYPE</code> + declaration. The Validator is more insistent on this point than + WebTechs was, which would insert a <code>DOCTYPE</code> on the fly + for you; The Validator requires that your <code>DOCTYPE</code> already + be in the document. + </p> + <p> + So now you're preparing to add a <code>DOCTYPE</code> to your document. + Be sure that the syntax is as described above, and that you use the + correct public identifier; otherwise, The Validator will use the wrong + DTD, or will be unable to find a DTD at all, and will produce a huge + list of absolutely meaningless errors. The Validator's + <a href="catalog">public identifier catalog</a> lists all the public + identifiers The Validator recognizes for various types of HTML; of + those, the following public identifiers are most likely to be widely + recognized: + </p> + <dl> + <dt><code>For HTML 2.0...</code></dt><dd>...use "-//IETF//DTD HTML 2.0//EN"</dd> + <dt><code>For HTML 4.0...</code></dt><dd>...use "-//W3C//DTD HTML 4.0//EN"</dd> + <dt><code>For HTML 4.0 Transitional...</code></dt><dd>...use "-//W3C//DTD HTML 4.0 Transitional//EN"</dd> + <dt><code>For HTML 4.0 Frameset...</code></dt><dd>...use "-//W3C//DTD HTML 4.0 Framset//EN"</dd> + </dl> + <p>Note that the string must appear exactly as shown, including case.</p> + <p class="warning"> + <strong>WARNING:</strong></a> Some HTML editors will insert a + <code>DOCTYPE</code> declaration for you. Unfortunately, this + pre-inserted <code>DOCTYPE</code> will sometimes confuse + The Validator. This usually occurs when the inserted + <code>DOCTYPE</code> does not correspond to the generated HTML. + If your editor adds a <code>DOCTYPE</code> to your page, you may + need to correct it as described above before running your page through + The Validator. + </p> + </div> + </body> +</html> + |