HTTP0.9Summary.html
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<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="generator" content=
"HTML Tidy for Mac OS X (vers 31 October 2006 - Apple Inc. build 13), see www.w3.org" />
<title>
HTTP0.9 Summary -- /DesignIssues
</title>
<nextid />
</head>
<body bgcolor="#FFC060" text="#302005">
<a href="OldDocs.html"><img src=
"../Icons/WWW/arch1992.gif" /></a>
<hr />
<address>
92.06.11 RC, TBL
</address>
<h1>
Summary of HTTP 0.9
</h1>The current version of <a name="2" href=
"../Protocols/HTTP/AsImplemented.html">HTTP</a> can be summed
up as follows:
<ul>
<li>A browser only sends the command GET followed by a
server/document identification optionally followed by a
question mark and a list of keywords (with no spaces). This
we call a UDI
</li>
<li>A server replies to a GET by supplying a piece of ASCII
text marked up in HTML, whereby just plain text with no tags
at all is acceptable. [but should be prefixed with PLAINTEXT
because the default style for HTML is (a mistake??) free
format.]
</li>
<li>the server holds no state w.r.t. the browser.
</li>
<li>if a document contains anywhere the ISINDEX tag then the
browser takes this to mean that a valid UDI from this
document to another one may be generated by taking the
current identifier and appending the keywords given in the
search panel.
</li>
</ul>Note that if responses from the server are encoded into
HTML tags, then HTTP is very asymmetric: the command GET is not
in HTML. [Yes, but this is part of HTTP not HTML as <a name="3"
href="#point">you point out</a> - TBL]
<h3>
Advantages
</h3>There is nothing other than HTML marked up text coming out
of a server
<p>
The browser does not know whether a server serves an index or
a set of hypertext documents.
</p>
<h3>
Disadvantages
</h3><a name="point">There is no lexical distinction</a>
between what constitutes HTTP information, document contents,
document kind.
<p>
In particular, error messages are returned as documents and
may or may not be ignored by the user.
</p>
<h3>
<a name="1">Good Characteristics</a>
</h3>Both browsers and servers silently ignore things they
cannot handle:
<ul>
<li>the browser ignores unknown tags,
</li>
<li>the server ignores anything after the single GET argument
(document/serverid?keywords).
</li>
</ul>This should be carefully kept: it means the user is not
annoyed by messages he should not have to deal with (I am
always thinking of the innocent, naive user who just happens to
use WWW, not somebody hacking unix programs in C)
</body>
</html>