References

The HTML specification cites these works:

HTTP: HTTP: A Protocol for Networked Information. This document is available at http://www.w3.org/WWW/Protocols/HTTP/HTTP2.html.
MIME: N. Borenstein, N. Freed, MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies, 09/23/1993. (Pages=81) (Format=.txt, .ps) (Obsoletes RFC1341) (Updated by RFC1590).
SGML: ISO 8879:1986, Information Processing Text and Office Systems Standard Generalized Markup Language (SGML).
SGMLS: An SGML parser by James Clark, jjc@jclark.com, derived from the ARCSGML parser materials which were written by Charles F. Goldfarb. The source is available at ftp.ifi.uio.no/pub/SGML/SGMLS.
URI: Universal Resource Identifiers. RFCxxx. Available by anonymous FTP as Postscript (info.cern.ch/pub/www/doc/url.ps) or text (info.cern.ch/pub/www/doc/url.txt)
W3: The World-Wide Web , a global information initiative. For bootstrap information, telnet info.cern.ch or find documents by ftp://info.cern.ch/pub/www/doc.