One document matched: draft-ietf-html-spec-03.txt
Differences from draft-ietf-html-spec-02.txt
HTML Working Group T. Berners-Lee
INTERNET-DRAFT MIT/W3C
<draft-ietf-html-spec-03.txt> D. Connolly
Expires: In six months May 31, 1995
Hypertext Markup Language - 2.0
CONTENTS
1. Introduction
2. HTML as an Application of SGML
3. HTML as an Internet Media Type
4. Document Structure
5. Character, Words, and Paragraphs
6. Hyperlinks
7. Forms
8. HTML Public Text
9. Glossary
10. Bibliography
11. Appendices
12. Acknowledgments
Status of this Memo
This document is an Internet-Draft. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas,
and its working groups. Note that other groups may also distribute
working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as ``work in progress.''
To learn the current status of any Internet-Draft, please check the
1id-abstracts.txt listing contained in the Internet-Drafts Shadow
Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe),
munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or
ftp.isi.edu (US West Coast).
Distribution of this document is unlimited. Please send comments to
the HTML working group (HTML-WG) of the Internet Engineering Task
Force (IETF) at <html-wg@oclc.org>. Discussions of the group are
archived at <URL:http://www.acl.lanl.gov/HTML_WG/archives.html>.
In this draft, the first three sections are considered essentially
finished. Sections 4 and 5 have been significantly revised and are
open to comments, though I'm fairly happy with those parts. Section 6
is somewhat new: it collects all information about hyperlinking into
one place. Sections 7 (forms elements) has also been revised, and
there are a few points I'm not sure on. The glossary (section 8) has
also been tweaked. Section 8 ``public text'' has been stable for some
time, but as it's critical, I'd appreciate a careful review just the
same.
ABSTRACT
The Hypertext Markup Language (HTML) is a simple markup
language used to create hypertext documents that are
platform independent. HTML documents are SGML documents with
generic semantics that are appropriate for representing
information from a wide range of domains. HTML markup can
represent hypertext news, mail, documentation, and
hypermedia; menus of options; database query results; simple
structured documents with in-lined graphics; and hypertext
views of existing bodies of information.
HTML has been in use by the World Wide Web (WWW) global
information initiative since 1990. This specification
roughly corresponds to the capabilities of HTML in common
use prior to June 1994. HTML is an application of ISO
Standard 8879:1986 Information Processing Text and Office
Systems; Standard Generalized Markup Language (SGML).
The `"text/html; version=2.0"' Internet Media Type (RFC
1590) and MIME Content Type (RFC 1521) is defined by this
specification.
1. Introduction
The HyperText Markup Language (HTML) is a simple data format
used to create hypertext documents that are portable from
one platform to another. HTML documents are SGML documents
with generic semantics that are appropriate for representing
information from a wide range of domains.
1.1. Scope
HTML has been in use by the World-Wide Web (WWW) global
information initiative since 1990. This specification
corresponds to the capabilities of HTML in common use prior
to June 1994 and referred to as ``HTML 2.0''.
HTML is an application of ISO Standard 8879:1986
_Information Processing Text and Office Systems; Standard
Generalized Markup Language_ (SGML). The HTML Document Type
Definition (DTD) is a formal definition of the HTML syntax
in terms of SGML.
This specification also defines HTML as an Internet Media
Type[IMEDIA] and MIME Content Type[MIME] called `text/html',
or `text/html; version=2.0'. As such, it defines the
semantics of the HTML syntax and how that syntax should be
interpreted by user agents.
1.2. Conformance
This specification governs the syntax of HTML documents and
the behaviour of HTML user agents.
1.2.1. Documents
A document is a conforming HTML document only if:
* It is a conforming SGML document, and it conforms to
the HTML DTD (see 8.1, "HTML DTD").
NOTE - There are a number of syntactic idioms that are
not supported or are supported inconsistently in some
historical user agent implementations. These idioms are
called out in notes like this throughout this
specification.
HTML documents should not contain these idioms, at
least until such time as support for them is widely
deployed.
* It conforms to the application conventions in this
specification. For example, the value of the HREF
attribute of the <A> element must conform to the URI
syntax.
* Its document character set includes ANSI/ISO 8859-1
and agrees with ISO/IEC 10646-1; that is, each code
position listed in 11.1, "The ANSI/ISO 8859-1 Coded
Character Set" is included, and each code position in
the document character set is mapped to the same
character as ISO10646 designates for that code
position.
NOTE - The document character set is somewhat
independent of the character encoding scheme used to
represent a document. For example, the ISO-2022-JP
character encoding scheme can be used for HTML
documents, since its repertoire is a subset of the
ISO10646 repertoire. The critical distinction is that
numeric character references agree with ISO10646
regardless of how the document is encoded.
The HTML DTD defines a standard HTML document type and
several variations, based on feature test entities:
HTML.Recommended
Certain features of the language are necessary for
compatibility with widespread usage, but they may
compromise the structural integrity of a document.
This feature test entity enables a more
prescriptive document type definition that
eliminates those features.
For example, in order to preserve the structure of
a document, an editing user agent may translate
HTML documents to the recommended subset, or it
may require that the documents be in the
recommended subset for import.
HTML.Deprecated
Certain features of the language are necessary for
compatibility with earlier versions of the
specification, but they tend to be used and
implemented inconsistently, and their use is
deprecated. This feature test entity enables a
document type definition that eliminates these
features.
Documents generated by tranlation software or
editing software should not contain these idioms.
1.2.2. User Agents
An HTML user agent conforms to this specification if:
* It parses the characters of an HTML document into
data characters and markup according to [SGML].
NOTE - In the interest of robustness and extensibility,
there are a number of widely deployed conventions for
handling non-conforming documents. See 3.2.1,
"Undeclared Markup Error Handling" for details.
* It supports the `ISO-8859-1' character encoding
scheme and processes each character in the ISO Latin
Alphabet No. 1 as specified in 5.1, "The ISO Latin 1
Character Repertoire".
NOTE - To support non-western writing systems, HTML
user agents should support ISO-10646-UCS-2 or similar
character encoding schemes and as much of the character
repertoire of ISO10646 as is practical.
* It behaves identically for documents whose parsed
token sequences are identical.
For example, comments and the whitespace in tags
disappear during tokenization, and hence they do not
influence the behaviour of conforming user agents.
* It allows the user to traverse (or at least attempt
to traverse, resources permitting) all hyperlinks in an
HTML document.
* It allows the user to express all form field values
specified in an HTML document and to (attempt to)
submit the values as requests to information services.
2. HTML as an Application of SGML
HTML is an application of ISO 8879:1986 -- Standard
Generalized Markup Language (SGML). SGML is a system for
defining structured document types and markup languages to
represent instances of those document types[SGML]. The
public text -- DTD and SGML declaration -- of the HTML
document type definition are provided in 8, "HTML Public
Text".
The term _HTML_ refers to both the document type defined
here and the markup language for representing instances of
this document type.
2.1. SGML Documents
An HTML document is an SGML document; that is, a sequence of
characters organized physically into a set of entities, and
logically as a hierarchy of elements.
The first production of the SGML grammar separates an SGML
document into three parts: an SGML declaration, a prologue,
and an instance. For the purposes of this specification, the
prologue is a DTD. This DTD describes another grammar: the
start symbol is given in the doctype declaration, the
terminals are data characters and tags, and the productions
are determined by the element declarations. The instance
must conform to the DTD, that is, it must be in the language
defined by this grammar.
The SGML declaration determines the lexicon of the grammar.
It specifies the document character set, which determines a
character repertoire that contains all characters that occur
in all text entities in the document, and the code positions
associated with those characters.
The SGML declaration also specifies the syntax-reference
character set of the document, and a few other parameters
that bind the abstract syntax of SGML to a concrete syntax.
This concrete syntax determines how the sequence of
characters of the document is mapped to a sequence of
terminals in the grammar of the prologue.
For example, consider the following document:
<!DOCTYPE html PUBLIC "-//IETF//DTD HTML 2.0//EN">
<title>Parsing Example</title>
<p>Some text. <em>*wow*</em></p>
An HTML user agent should use the SGML declaration that is
given in 8.2, "SGML Declaration for HTML". According to its
document character set, `*' refers to an asterisk
character.
The instance above is regarded as the following sequence of
terminals:
1. TITLE start-tag
2. data characters: ``Parsing Example''
3. TITLE end-tag
4. P start-tag
5. data characters ``Some text. ''
6. EM start-tag
7. ``*wow*''
8. EM end-tag
9. P end-tag
The start symbol of the DTD grammar is HTML, and the
productions are given in the public text identified by
`-//IETF//DTD HTML 2.0//EN' (8.1, "HTML DTD"). Hence the
terminals above parse as:
HTML
|
\-HEAD
| |
| \-TITLE
| |
| \-<TITLE>
| |
| \-"Parsing Example"
| |
| \-</TITLE>
|
\-BODY
|
\-P
|
\-<P>
|
\-"Some text. "
|
\-EM
| |
| \-<EM>
| |
| \-"*wow*"
| |
| \-</EM>
|
\-</P>
2.2. HTML Lexical Syntax
SGML specifies an abstract syntax and a reference concrete
syntax. Aside from certain quantities and capacities (e.g.
the limit on the length of a name), all HTML documents use
the reference concrete syntax. In particular, all markup
characters are in the repertoire of ISO 646 IRV. Data
characters are drawn from the document character set (see 5,
"Character, Words, and Paragraphs").
A complete discussion of SGML parsing, e.g. the mapping of a
sequence of characters to a sequence of tags and data, is
left to the SGML standard[SGML]. This section is only a
summary.
2.2.1. Data Characters
Any sequence of characters that do not constitute markup
(see 9.6 ``Delimiter Recognition'' of [SGML]) are mapped
directly to strings of data characters. Some markup also
maps to data character strings. Numeric character references
also map to single-character strings, via the document
character set. Each reference to one of the general entities
defined in the HTML DTD also maps to a single-character
string.
For example,
abc<def => "abc","<","def"
abc<def => "abc","<","def"
Note that the terminating semicolon is only necessary when
the character following the reference would otherwise be
recognized as markup:
abc < def => "abc ","<"," def"
abc < def => "abc ","<"," def"
And note that an ampersand is only recognized as markup when
it is followed by a letter or digit:
abc & lt def => "abc & lt def"
abc & 60 def => "abc & 60 def"
A useful technique for translating plain text to HTML is to
replace each '<', '&', and '>' by an entity reference or
numeric character reference as follows:
ENTITY NUMERIC
CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION
& & & Ampersand
< < < Less than
> > > Greater than
NOTE - There are SGML mechanisms, CDATA and RCDATA, to
allow most `<', `>', and `&' characters to be entered
without the use of entity references. Because these
features tend to be used and implemented
inconsistently, and because they conflict with
techniques for reducing HTML to 7 bit ASCII for
transport, they are not used in this version of the
HTML DTD.
2.2.2. Tags
Tags delimit elements such as headings, paragraphs, lists,
character highlighting, and links. Most HTML elements are
identified in a document as a start-tag, which gives the
element name and attributes, followed by the content,
followed by the end tag. Start-tags are delimited by `<' and
`>'; end tags are delimited by `</' and `>'. An example is:
<H1>This is a Heading</H1>
Some elements only have a start-tag without an end-tag. For
example, to create a line break, you use the `<BR>' tag.
Additionally, the end tags of some other elements, such as
Paragraph (`</P>'), List Item (`</LI>'), Definition Term
(`</DT>'), and Definition Description (`<DD>') elements, may
be omitted.
The content of an element is a sequence of data character
strings and nested elements. Some elements, such as anchors,
cannot be nested. Anchors and character highlighting may be
put inside other constructs. See the HTML DTD, 8.1, "HTML
DTD" for full details.
NOTE - The SGML declaration for HTML specifies SHORTTAG
YES, which means that there are other valid syntaxes
for tags, such as NET tags, `<EM/.../'; empty start
tags, `<>'; and empty end-tags, `</>'. Until support
for these idioms is widely deployed, their use is
strongly discouraged.
2.2.3. Names
A name consists of a letter followed by up to 71 letters,
digits, periods, or hyphens. Element names are not case
sensitive, but entity names are. For example,
`<BLOCKQUOTE>', `<BlockQuote>', and `<blockquote>' are
equivalent, whereas `&' is different from `&'.
In a start-tag, the element name must immediately follow the
tag open delimiter `<'.
2.2.4. Attributes
In a start-tag, white space and attributes are allowed
between the element name and the closing delimiter. An
attribute typically consists of an attribute name, an equal
sign, and a value, though some attributes may be just a
value. White space is allowed around the equal sign.
The value of the attribute may be either:
* A string literal, delimited by single quotes or
double quotes and not containing any occurrences of the
delimiting character.
NOTE - Some historical implementations consider any
occurrence of the `>' character to signal the end of a
tag. For compatibility with such implementations, when
`>' appears in an attribute value, it should be
represented with a numeric character reference. For
example, `<IMG SRC="eq1.jpg" alt="a>b">' should be
written `<IMG SRC="eq1.jpg" alt="a>b">' or `<IMG
SRC="eq1.jpg" alt="a>b">'.
* A name token (a sequence of letters, digits, periods,
or hyphens).
NOTE - Some historical implementations allow any
character except space or `>' in a name token.
In this example, <img> is the element name, src is the
attribute name, and `http://host/dir/file.gif' is the
attribute value:
<img src='http://host/dir/file.gif'>
A useful technique for computing an attribute value literal
for a given string is to replace each quote and space
character by an entity reference or numeric character
reference as follows:
ENTITY NUMERIC
CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION
TAB Tab
LF
Line Feed
CR
Carriage Return
Space
" " " Quotation mark
& & & Ampersand
For example:
<IMG SRC="image.jpg" alt="First "real" example">
Note that the SGML declaration in section 13.3 limits the
length of an attribute value to 1024 characters.
Attributes such as ISMAP and COMPACT may be written using a
minimized syntax. The markup:
<UL COMPACT="compact">
can be written using a minimized syntax:
<UL COMPACT>
NOTE - Some historical implementations only understand
the minimized syntax.
2.2.5. Comments
To include comments in an HTML document, use a comment
declaration. A comment declaration consists of `<!' followed
by zero or more comments followed by `>'. Each comment
starts with `--' and includes all text up to and including
the next occurrence of `--'. In a comment declaration, white
space is allowed after each comment, but not before the
first comment. The entire comment declaration is ignored.
NOTE - Some historical HTML implementations incorrectly
consider any `>' character to be the termination of a
comment.
For example:
<HEAD>
<TITLE>HTML Comment Example</TITLE>
<!-- Id: html-sgml.sgm,v 1.5 1995/05/26 21:29:50 connolly Exp -->
<!-- another -- -- comment -->
<!>
</HEAD>
<BODY>
<p> <!- not a comment, just regular old data characters ->
2.2.6. Example HTML Document
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<HTML>
<!-- Here's a good place to put a comment. -->
<HEAD>
<TITLE>Structural Example</TITLE>
</HEAD><BODY>
<H1>First Header</H1>
<P>This is a paragraph in the example HTML file. Keep in mind
that the title does not appear in the document text, but that
the header (defined by H1) does.</P>
<OL>
<LI>First item in an ordered list.
<LI>Second item in an ordered list.
<UL COMPACT>
<LI> Note that lists can be nested;
<LI> Whitespace may be used to assist in reading the
HTML source.
</UL>
<LI>Third item in an ordered list.
</OL>
<P>This is an additional paragraph. Technically, end tags are
not required for paragraphs, although they are allowed. You can
include character highlighting in a paragraph. <EM>This sentence
of the paragraph is emphasized.</EM> Note that the </P>
end tag has been omitted.
<P>
<IMG SRC ="triangle.xbm" alt="Warning: ">
Be sure to read these <b>bold instructions</b>.
</BODY></HTML>
3. HTML as an Internet Media Type
An HTML user agent allows users to interact with resources
which have HTML representations. At a minimum, it must allow
users to examine and navigate the content of HTML level 1
documents. HTML user agents should be able to preserve all
formatting distinctions represented in an HTML document, and
be able to simultaneously present resources referred to by
IMG elements (they may ignore some formatting distinctions
or IMG resources at the request of the user). Conforming
HTML user agents should support form entry and submission.
3.1. text/html media type
This specification defines the Internet Media Type[IMEDIA]
(formerly referred to as the Content Type[MIME]) called
`text/html'. The following is to be registered with [IANA].
Media Type name
text
Media subtype
name
html
Required
parameters
none
Optional
parameters
level, charset
Encoding
considerations
any encoding is allowed
Security
considerations
see 3.3, "Security Considerations"
The optional parameters are defined as follows:
Level
The level parameter specifies the feature set used
in the document. The level is an integer number,
implying that any features of same or lower level
may be present in the document. Level 1 is all
features defined in this specification except
those that require the <FORM> element. Level 2
includes form processing. Level 2 is the default.
Charset
The charset parameter (as defined in section 7.1.1
of RFC 1521[MIME]) may be given to specify the
character encoding scheme used to represent the
HTML document as a sequence of octets. The default
value is outside the scope of this specification;
but for example, the default is `US-ASCII' in the
context of MIME mail, and `ISO-8859-1' in the
context of HTTP.
3.2. HTML Document Representation
A message entity with a content type of `text/html'
represents an HTML document, consisting of a single text
entity. The `charset' parameter (whether implicit or
explicit) identifies a character encoding scheme. The text
entity consists of the characters determined by this
character encoding scheme and the octets of the body of the
message entity.
3.2.1. Undeclared Markup Error Handling
To facilitate experimentation and interoperability between
implementations of various versions of HTML, the installed
base of HTML user agents supports a superset of the HTML 2.0
language by reducing it to HTML 2.0: markup in the form of a
start-tag or end-tag whose generic identifier is not
declared is mapped to nothing during tokenization.
Undeclared attributes are treated similarly. The entire
attribute specification of an unknown attribute (i.e., the
unknown attribute and its value, if any) should be ignored.
On the other hand, references to undeclared entities should
be treated as data characters.
For example:
<div class=chapter><h1>foo</h1><p>...</div>
=> <H1>,"foo",</H1>,<P>,"..."
xxx <P ID=z23> yyy
=> "xxx ",<P>," yyy
Let α and β be finite sets.
=> "Let α and β be finite sets."
Support for notifying the user of such errors is encouraged.
Information providers are warned that this convention is not
binding: unspecified behavior may result, as such markup is
not conforming to this specification.
3.2.2. Conventional Representation of Newlines
SGML specifies that a text entity is a sequence of records,
each beginning with a record start character and ending with
a record end character (code positions 10 and 13
respectively) (section 7.6.1, ``Record Boundaries'' in
[SGML]).
[MIME] specifies that a body of type `text/*' is a sequence
of lines, each terminated by CRLF, that is, octets 10, 13.
In practice, HTML documents are frequently represented and
transmitted using an end of line convention that depends on
the conventions of the source of the document; frequently,
that representation consists of CR only, LF only, or a CR LF
sequence. Hence the decoding of the octets will often result
in a text entity with some missing record start and record
end characters.
Since there is no ambiguity, HTML user agents are encouraged
to infer the missing record start and end characters.
An HTML user agent should treat end of line in any of its
variations as a word space in all contexts except
preformatted text. Within preformatted text, an HTML user
agent should treat any of the three common representations
of end-of-line as starting a new line.
3.3. Security Considerations
Anchors, embedded images, and all other elements which
contain URIs as parameters may cause the URI to be
dereferenced in response to user input. In this case, the
security considerations of the URI specification apply.
The widely deployed methods for submitting forms requests --
HTTP and SMTP -- provide little assurance of
confidentiality. Information providers who request sensitive
information via forms -- especially by way of the `PASSWORD'
type input field (see 7.1.2, "Input Field: INPUT") -- should
be aware and make their users aware of the lack of
confidentiality.
4. Document Structure
To identify information as an HTML document conforming to
this specification, each document should start with the
following prologue:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
NOTE - If the body of a `text/html' message entity does
not begin with a document type declaration, an HTML
user agent should infer the above document type
declaration.
HTML user agents are required to support the above document
type declaration and the following document type
declarations:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Level 2//EN">
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN">
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Strict//EN">
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict//EN">
They are not required to support other document types, but
they may. In particular, they may support other formal
public identifiers, or other document types altogether. They
may support an internal declaration subset with supplemental
entity, element, and other markup declarations, or they may
not.
4.1. Document Element: <HTML>
The HTML document element consists of a head and a body,
much like a memo or a mail message. The head contains the
title and other optional elements. The body is a text flow
consisting of paragraphs, lists, and other elements.
4.2. Head: <HEAD>
The head of an HTML document is an unordered collection of
information about the document. For example:
<HEAD>
<TITLE>Introduction to HTML</TITLE>
</HEAD>
4.2.1. Title: <TITLE>
Every HTML document must contain a <TITLE> element.
The title should identify the contents of the document in a
global context. A short title, such as ``Introduction'' may
be meaningless out of context. A title such as
``Introduction to HTML Elements'' is more appropriate.
NOTE - The length of a title is not limited; however,
long titles may be truncated in some applications. To
minimize this possibility, titles should be fewer than
64 characters.
A user agent may display the title of a document in a
history list or as a label for the window displaying the
document. Contrast with headings (4.4, "Headings: H1 ...
H6"), which are typically displayed with the body text flow.
4.2.2. Base URI: <BASE>
The optional <BASE> element specifies the URI of the
document, overriding any context otherwise known to the user
agent. The required HREF attribute specifies the URI for
navigating the document (see 6, "Hyperlinks"). The value of
the HREF attribute must be an absolute URI.
4.2.3. Keyword Index: <ISINDEX>
The <ISINDEX> element indicates that the user agent should
allow the user to search an index by giving keywords. See
6.3, "Queries and Indexes" for details.
4.2.4. Link: <LINK>
The <LINK> element represents a hyperlink. It is typically
used to indicate authorship, related indexes and glossaries,
older or more recent versions, stylesheets, document
hierarchy etc.
4.2.5. Associated Metainformation: <META>
The <META> element is an extensible container for use in
identifying, indexing, and cataloging specialized document
metainformation. Metainformation has two main functions:
* to provide a means to discover that the data set
exists and how it might be obtained or accessed; and
* to document the content, quality, and features of a
data set and so give an indication of its fitness for
use.
Each <META> element specifies a name/value pair. If multiple
META elements are provided with the same name, their
combined contents--concatenated as a comma-separated
list--is the value associated with that name.
NOTE - The <META> element should not be used where a
specific element such as <TITLE> would be appropriate.
HTTP servers should read the content of the document <HEAD>
to generate header fields corresponding to any elements
defining a value for the attribute HTTP-EQUIV.
NOTE - The method by which the server extracts document
metainformation is unspecified and not mandatory. The
META element only provides an extensible mechanism for
identifying and embedding document metainformation -
how it may be used is up to the individual server
implementation and the HTML user agent.
Attributes of the META element:
HTTP-EQUIV
This attribute binds the element to an HTTP header
field. An HTTP server may use this information to
process the doducment. In particular, it should
include a header field in the responses to GET
requests for this document: the header name is
taken from the HTTP-EQUIV attribute value, and the
header value is taken from the value of the
CONTENT attribute. HTTP header names are not case
sensitive.
NAME
name of the name/value pair. If not present,
HTTP-EQUIV gives the name.
CONTENT
The value of the name/value pair.
Examples
If the document contains:
<META HTTP-EQUIV="Expires"
CONTENT="Tue, 04 Dec 1993 21:29:02 GMT">
<meta http-equiv="Keywords" CONTENT="Fred, Barney">
<META HTTP-EQUIV="Reply-to"
content="fielding@ics.uci.edu (Roy Fielding)">
then the server should include the following header fields:
Expires: Tue, 04 Dec 1993 21:29:02 GMT
Keywords: Fred, Barney
Reply-to: fielding@ics.uci.edu (Roy Fielding)
as part of the HTTP response to a `GET' or `HEAD' request
for that document.
When the HTTP-EQUIV attribute is not present, the server
should not generate an HTTP response header for the
metainformation; e.g.,
Do not name an HTTP-EQUIV equal to a response header that
should normally only be generated by the HTTP server.
Example names that are inappropriate include `Server',
`Date', and `Last-modified' -- the exact list of
inappropriate names is dependent on the particular server
implementation.
4.2.6. Next Id: <NEXTID>
They <NEXTID> element gives a hint for the name to use for
an <A> element when editing an HTML document. It should be
distinct from all NAME attribute values on <A> elements. For
example:
<NEXTID N=Z27>
4.3. Body: <BODY>
The <BODY> element contains the text flow of the document,
including headings, paragraphs, lists, etc.
For example:
<BODY>
<h1>Important Stuff</h1>
<p>Explanation about important stuff...
</BODY>
4.4. Headings: <H1> ... <H6>
The six heading elements, <H1> through <H6>, denote section
headings. Although the order and occurence of headings is
not constrained by the HTML DTD, documents should not skip
levels (for example, from H1 to H3), as converting such
documents to other representations is often problematic.
Example of use:
<H1>This is a heading</H1>
Here is some text
<H2>Second level heading</H2>
Here is some more text.
Typical renderings are:
H1
Bold, very-large font, centered. One or two blank
lines above and below.
H2
Bold, large font, flush-left. One or two blank
lines above and below.
H3
Italic, large font, slightly indented from the
left margin. One or two blank lines above and
below.
H4
Bold, normal font, indented more than H3. One
blank line above and below.
H5
Italic, normal font, indented as H4. One blank
line above.
H6
Bold, indented same as normal text, more than H5.
One blank line above.
4.5. Block Structuring Elements
Each of the following elements defines a block structure;
that is, they indicate a paragraph break before and after.
4.5.1. Paragraph: <P>
The <P> element indicates a paragraph. The exact
indentation, leading space, etc. of a paragraph is not
specified and may be a function of other tags, style sheets,
etc.
Typically, paragraphs are surrounded by a vertical space of
one line or half a line. The first line in a paragraph is
indented in some cases.
Example of use:
<H1>This Heading Precedes the Paragraph</H1>
<P>This is the text of the first paragraph.
<P>This is the text of the second paragraph. Although you do not
need to start paragraphs on new lines, maintaining this
convention facilitates document maintenance.</P>
<P>This is the text of a third paragraph.</P>
4.5.2. Preformatted Text: <PRE>
The <PRE> element represents a character cell block of
textand so is suitable for text that has been formatted on
screen.
The <PRE> tag may be used with the optional WIDTH attribute.
The WIDTH attribute specifies the maximum number of
characters for a line and allows the HTML user agent to
select a suitable font and indentation.
Within preformatted text:
* Line breaks within the text are rendered as a move to
the beginning of the next line.
NOTE - References to the ``beginning of a new line'' do
not imply that the renderer is forbidden from using a
constant left indent for rendering preformatted text.
The left indent may be constrained by the width
required.
* Anchor elements and phrase markup may be used.
NOTE - Within a Preformatted Text element, the
constraint that the rendering must be on a fixed
horizontal character pitch may limit or prevent the
ability of the HTML user agent to faithfully render
phrase markup.
* Elements that define paragraph formatting (headings,
address, etc.) must not be used.
NOTE - Som historical documents contain <P> tags in
<PRE> elements. User agents are engcouraged to treat
this a a line break. A <P> tag followed by a newline
character should produce only one line break, not a
line break plus a blank line.
* The horizontal tab character (encoded in `US-ASCII'
and `ISO-8859-1' as decimal 9) must be interpreted as
the smallest positive nonzero number of spaces which
will leave the number of characters so far on the line
as a multiple of 8.
Example of use:
<PRE>
This is an example line.
</PRE>
4.5.3. Address: <ADDRESS>
The <ADDRESS> element specifies such information as address,
signature and authorship, often at the beginning or end of
the body of a document.
Typically, the <ADDRESS> element is rendered in an italic
typeface and may be indented.
Example of use:
<ADDRESS>
Newsletter editor<BR>
J.R. Brown<BR>
JimquickPost News, Jumquick, CT 01234<BR>
Tel (123) 456 7890
</ADDRESS>
4.5.4. Block Quote: <BLOCKQUOTE>
The <BLOCKQUOTE> element contains text quoted from another
source.
A typical rendering might be a slight extra left and right
indent, and/or italic font. The <BLOCKQUOTE> typically
provides space above and below the quote.
Single-font rendition may reflect the quotation style of
Internet mail by putting a vertical line of graphic
characters, such as the greater than symbol (>), in the left
margin.
Example of use:
I think the poem ends
<BLOCKQUOTE>
<P>Soft you now, the fair Ophelia. Nymph, in thy orisons, be all
my sins remembered.
</BLOCKQUOTE>
but I am not sure.
4.6. List Elements
HTML includes a number of list elements. They may be used in
combination; for example, a <OL> may be nested in an <LI>
element of a <UL>.
4.6.1. Unordered List: <UL>, <LI>
The <UL> represents a list of items with no inherent
ordering -- typically a bulleted list.
The content of a <UL> element is a sequence of <LI>
elements. For example:
<UL>
<LI>First list item
<LI>Second list item
<p>second paragraph of second item
<LI>Third list item
</UL>
4.6.2. Ordered List: <OL>
The <UL> element represents an ordered list of items, sorted
by sequence or order of importance.
The content of a <OL> element is a sequence of <LI>
elements. For example:
<OL>
<LI>Click the Web button to open the Open the URI window.
<LI>Enter the URI number in the text field of the Open URI
window. The Web document you specified is displayed.
<ol>
<li>substep 1
<li>substep 2
</ol>
<LI>Click highlighted text to move from one link to another.
</OL>
The COMPACT attribute suggests that a compact rendering be
used.
4.6.3. Directory List: <DIR>
The <DIR> element is similar to the <UL> element. It
represents a list of short items, typically up to 20
characters each. Items in a directory list may be arranged
in columns, typically 24 characters wide.
The content of a <OL> element is a sequence of <LI>
elements. Nested block elements are not allowed in the
content of <DIR> elements. For example:
<DIR>
<LI>A-H<LI>I-M
<LI>M-R<LI>S-Z
</DIR>
4.6.4. Menu List: <MENU>
The <MENU> element is a list of items with typically one
line per item. The menu list style is typically more compact
than the style of an unordered list.
The content of a <MENU> element is a sequence of <LI>
elements. Nested block elements are not allowed in the
content of <MENU> elements. For example:
<MENU>
<LI>First item in the list.
<LI>Second item in the list.
<LI>Third item in the list.
</MENU>
4.6.5. Definition List: <DL>, <DT>, <DD>
A definition list is a list of terms and corresponding
definitions. Definition lists are typically formatted with
the term flush-left and the definition, formatted paragraph
style, indented after the term.
Example of use:
<DL>
<DT>Term<DD>This is the definition of the first term.
<DT>Term<DD>This is the definition of the second term.
</DL>
If the DT term does not fit in the DT column (one third of
the display area), it may be extended across the page with
the DD section moved to the next line, or it may be wrapped
onto successive lines of the left hand column.
The optional COMPACT attribute suggests that a compact
rendering be used, because the list items are small and/or
the entire list is large.
Unless the COMPACT attribute is present, an HTML user agent
may leave white space between successive DT, DD pairs. The
COMPACT attribute may also reduce the width of the left-hand
(DT) column.
<DL COMPACT>
<DT>Term<DD>This is the first definition in compact format.
<DT>Term<DD>This is the second definition in compact format.
</DL>
4.7. Phrase Markup
Phrases may be marked up according to idiomatic usage,
typographic appearance, or for use as hyperlink anchors.
User agents must render highlighted phrases distinctly from
plain text. Additionally, <EM> content must be rendered as
distinct from <STRONG> content, and <B> content must
rendered as distinct from <I> content.
Phrase elements may be nested within the content of other
phrase elements; however, HTML user agents may render nested
phrase elements indistinctly from non-nested elements:
plain <B>bold <I>italic</I></B> may the rendered
the same as plain <B>bold </B><I>italic</I>
4.7.1. Idiomatic Elements
4.7.1.1. Citation: <CITE>
The <CITE> element is used to indicate the title of a book
or other citation. It is typically typeset as italics. For
example:
He just couldn't get enough of <cite>The Grapes of Wrath</cite>.
4.7.1.2. Code: <CODE>
The <CODE> element indicates an example of code, typically
rendered in a monospaced font. Contrast with the <PRE> block
structuring element in 4.5.2, "Preformatted Text: PRE". For
example:
The expression <code>x += 1</code> is short for <code>x = x + 1</code>.
4.7.1.3. Emphasis: <EM>
The <EM> element indicates an emphasized phrase, typically
rendered as italics. For example:
A singular subject <em>always</em> takes a singular verb.
4.7.1.4. Keyboard: <KBD>
The Keyboard element indicates text typed by a user,
typically rendered in a monospaced font. This is commonly
used in instruction manuals. For example:
Enter <kbd>FIND IT</kbd> to search the database.
4.7.1.5. Sample: <SAMP>
The <SAMP> element indicates a sequence of literal
characters, typically rendered in a monospaced font. For
example:
The only word containing the letters <samp>mt</samp> is dreamt.
4.7.1.6. Strong Empasis: <STRONG>
The <STRONG> element indicates strong emphasis, typically
rendered in bold. For example:
<strong>STOP</strong>, or I'll say "<strong>STOP</strong>" again!.
4.7.1.7. Variable: <VAR>
The <VAR> element indicates a placeholder, typically
rendered as italic. For example:
Take a guess: Roses are <var>blank</var>.
4.7.2. Typographic Elements
Typographic elements are used to specify the format of
marked text.
Typical renderings for idomatic elements vary between user
agents. If a specific rendering is necessary -- for example,
when referring to a specific text attribute as in ``The
italic parts are mandatory'' -- a typographic element can be
used to ensure that the intended typography is used where
possible.
4.7.2.1. Bold: <B>
The <B> element indicated bold text. Where bold typography
is unavailable, an alternative representation may be used.
4.7.2.2. Italic: <I>
The <I> element indicated italic text. Where italic
typography is unavailable, an alternative representation may
be used.
4.7.2.3. Typewriter: <TT>
The <TT> element indicates typewriter text. Where a
typewriter font is unavailable, an alternative
representation may be used.
4.7.3. Anchor: <A>
The <A> element indicates the source and/or destination of a
hyperlink (see 6, "Hyperlinks"). At least one of the NAME
and HREF attributes should be given. Attributes of the <A>
element:
HREF
gives the destination of a hyperlink.
NAME
gives the name of the anchor, and makes it
available as a navigation destination.
TITLE
suggests a title for the destination resource --
advisory only. The TITLE attribute may be used:
* for display prior to accessing the destination
resource, for example, as a margin note or on a small
box while the mouse is over the anchor, or while the
document is being loaded;
* for resources that do not specify a title such as
graphics, plain text and Gopher menus, for use as a
window title.
REL
The REL attribute gives the relationship(s)
described by the hyperlink. The value is a
whitespace separated list of relationship names.
REV
same as the REL attribute, but the semantics of
the relationship are in the reverse direction. A
link from A to B with REL=``X'' expresses the same
relationship as a link from B to A with REV=``X''.
An anchor may have both REL and REV attributes.
URN
specifies a preferred, more persistent identifier
for the destination. The format of URNs is under
discussion (1995) by various working groups of the
Internet Engineering Task Force.
METHODS
specifies methods to be used in accessing the
destination, as a whitespace-separated list of
names. For similar reasons as for the TITLE
attribute, it may be useful to include the
information in advance in the link. For example,
the HTML user agent may chose a different
rendering as a function of the methods allowed;
for example, something that is searchable may get
a different icon.
4.8. Line Break: <BR>
The <BR> element specifies a line break between words (see
5, "Character, Words, and Paragraphs"). For example:
<P> Pease porridge hot<BR>
Pease porridge cold<BR>
Pease porridge in the pot<BR>
Nine days old.
4.9. Horizontal Rule: <HR>
The <HR> element is a divider between sections of text;
typcially a full width horizontal rule or equivalent
graphic. For example:
<HR>
<ADDRESS>February 8, 1995, CERN</ADDRESS>
</BODY>
4.10. Image: <IMG>
The <IMG> element refers to an image or icon.
HTML user agents that cannot process images ignore the <IMG>
element unless it the ALT attribute is present.
NOTE - Some HTML user agents can process graphics
linked via anchors , but not <IMG> graphics. If a
graphic is essential, it should be referenced from an
<A> element rather than in <IMG> element.If the graphic
is not essential, then the <IMG> element is
appropriate.
Attributes of the <IMG> element:
ALIGN
alignment of the image with respect to the text
baseline. * `TOP' specifies that the top of the image
aligns with the tallest item on the line contianing the
image.
* `MIDDLE' specifies that the center of the image
aligns with the baseline of the line containing the
image.
* `BOTTOM' specifies that the bottom of the image
aligns with the baseline of the line containing the
image.
ALT
Optional alternative text, for use in
non-graphical environments.
ISMAP
indicates an image map (see 6.4, "Image Maps").
SRC
specifies the URI of the image resource.
NOTE - In practice, the media types of image resources
are limited to a few raster graphic formats: typically
`image/gif', `image/jpeg'. In particular, `text/html'
resources are not intended to be used as image
resources.
Examples of use:
<IMG SRC="triangle.xbm" ALT="Warning:"> Be sure
to read these instructions.
<IMG SRC="triangle.xbm">Be sure to read these
instructions.
<a href="http://machine/htbin/imagemap/sample">
<IMG SRC="sample.xbm" ISMAP>
</a>
5. Character, Words, and Paragraphs
An HTML user agent should present the body of an HTML
document as a collection of typeset paragraphs and
preformatted text. Except for the <PRE> element, each block
structuring element is regarded as a paragraph by taking the
data characters in its content and the content of its
descendant elements, concatenating them, and splitting the
result into words, separated by space, tab, or record end
characters (and perhaps hyphen characters). The sequence of
words is typeset as a paragraph by breaking it into lines.
5.1. The ISO Latin 1 Character Repertoire
The minimum character repertoire supported by all conforming
HTML user agents is Latin Alphabet Nr. 1, or simply Latin-1.
Latin-1 includes characters from most Western European
languages, as well as a number of control characters.
Latin-1 also includes a non-breaking space, a soft hyphen
indicator, 93 graphical characters, 8 unassigned characters,
and 25 control characters.
NOTE - Use the non-breaking space and soft hyphen
indicator characters is discouraged because support for
them is not widely deployed.
NOTE - To support non-western writing systems, a larger
character repertoire will be specified in a future
version of HTML. The document character set will be
ISO/IEC 10646-1, or some subset that agrees with
ISO/IEC 10646-1; in particular, all numeric character
references must use code positions assigned by ISO/IEC
10646-1.
In SGML applications, the use of control characters is
limited in order to maximize the chance of successful
interchange over heterogeneous networks and operating
systems. In HTML, only three control characters are allowed:
Horizontal Tab (HT, encoded as 9 decimal in `US-ASCII' and
`ISO-8859-1'), Carriage Return, and Line Feed.
The HTML DTD references the Added Latin 1 entity set, to
allow mnemonic representation of Latin 1 characters using
only the widely supported ASCII character repertoire. For
example:
Kurt Gödel was a famous logician and mathematician.
See 8.4.2, "ISO Latin 1 Character Entity Set" for a table of
the ``Added Latin 1'' entities, and 11.1, "The ANSI/ISO
8859-1 Coded Character Set" for a table of the code
positions of ANSI/ISO 8859-1.
6. Hyperlinks
In addition to general purpose elements such as paragraphs
and lists, HTML documents can express hyperlinks. A
hyperlink is a relationship between two resources, called
the source and the destination of the hyperlink. Each
resource has a Uniform Resource Identifier (URI).
An HTML user agent allows navigating a collection of these
resources. In the following interactions, the URI of the
source document is called the base URI.
6.1. Accessing Resources
Each of the following markup constructs is the source of a
hyperlink; these hyperlinks are references to resources to
be processed in conjunction with the source documents:
* <IMG> elements
* <INPUT> elements with the SRC attribute present
* <LINK> element
To access the destination of a hyperlink, the base URI of
the source document is combined with the value of the HREF
or SRC attribute of the hyperlink element according to
[RELURL]. The user agent disregards any fragment identifer,
and uses the resulting URI to access the destination
resource. For example, if a document identified as
`http://host/x/y.html' contains:
<img src="../icons/abc.gif">
then the user agent must use the URI
`http://host/icons/abc.gif' to access the resource linked
from the <IMG> element.
6.2. Traversing Hyperlinks
An <A> element with the HREF attribute present is an anchor;
that is, the source of a hyperlink that is an option to
navigate to another resource. The <LINK> element may also be
an anchor.
In addition to the base URI, the state of an HTML user agent
includes a list of the anchors in the document. The user can
traverse a hyperlink by choosing an anchor. The user agent
then accesses the destination document as above and presents
it.
6.2.1. Fragment Identifiers
If the value of the <HREF> attribute of an anchor element
contains a `#' character, then the characters after the `#'
are a fragment identifier, not a part of the destination
URI. As a degenerate case, `HREF="#fragment"' refers to an
anchor in the same document: the source and destination URIs
are the same.
After accessing the destination resource, the navigation
state (the scrollbar, for example) may be modified by a
fragment identifer in the hyperlink source markup. The
meaning of fragment identifiers depends on the media type of
the destination resource. For `text/html' resources, it
instructs the user agent to locate the <A> element with a
NAME attribute whose value is the same as the fragment
identifier. The matching is case sensitive.
For example, if a user agent was processing the above
document and the user indicated the following anchor:
<p> See: <a href="app1.html#bannanas">appendix 1</a> for more detail
on bannanas.</a>
then the user agent URI must access the resource
`http://host/x/app1.html'. Assuming the resource is
represented using the `text/html' media type, the user agent
must locate the anchor named `bannanas' and begin navigation
there.
The base URI for navigating the destination document may be
different from the URI used to access it. For example, it
may be replaced by by a <BASE> tag in the destination
document or by an HTTP redirection transaction.
6.3. Queries and Indexes
The <ISINDEX> element represents a set of hyperlinks. The
user can choose from the set by providing keywords to the
user agent. The user agent computes the destination URI by
appending `?' and the keywords to the base URI. The keywords
are escaped according to [URL] and joined by `+'. For
example, if a document contains:
<BASE HREF="http://host/index">
<ISINDEX>
and the user provides the keywords `apple' and `berry', then
the user agent must access the resource
`http://host/index?apple+berry'.
<FORM> elements with `METHOD=GET' also represent sets of
hyperlinks. See 7.2.2, "Query Forms: METHOD=GET" for
details.
6.4. Image Maps
The ISMAP attribute in combination with the <A> and <IMG>
elements, represents a set of hyperlinks. The user can
choose from the set by choosing a pixel of the image. The
user agent computes the destination URI by appending `?' and
the coordinates of the pixel to the URI given in the <A>
element. For example, if a document contains:
<head><title>ImageMap Example</title>
<BASE HREF="http://host/index"></head>
<body>
<p> Choose any of these icons:<br>
<a href="/cgi-bin/imagemap"><img ismap src="icons.gif"></a>
and the user chooses the upper-leftmost pixel, then chosen
hyperlink is the one with the URI
`http://host/cgi-bin/image?0,0'.
7. Forms
A form is a template for a form data set -- sequence of
name/value pair fields -- with an associated method and
action URI. The names are specified on the NAME attributes
of form input elements, and the values are given by the
user. The resulting form data set is used to access an
information service as a function of the action and method.
Forms elements can be mixed in with document structuring
elements. For example, a <PRE> element may contain a <FORM>
element, or a <FORM> element may contain lists which contain
<INPUT> elements. This gives considerable flexibility in
designing the layout of forms.
Form processing is a level 2 feature.
7.1. Form Elements
7.1.1. Form: <FORM>
The <FORM> element contains a sequence of input elements,
along with document structuring elements. The attributes
are:
ACTION
specifies the action URI for the form. The ACTION
attribute defaults to the base URI of the document
(see 6, "Hyperlinks").
METHOD
selects a method of accessing the action URI.
ENCTYPE
specifies the media type used to encode the
name/value pairs for transport, in case the
protocol does not itself impose a format.
7.1.2. Input Field: <INPUT>
The <INPUT> element represents a field for user input.
Attributes are:
ALIGN
vertical alignment of the image. For use only with
`TYPE=IMAGE'. The possible values are as for the
ALIGN attribute of the <IMG> element (see 4.10,
"Image: IMG").
CHECKED
indicates that the initial state of a checkbox or
radio button is selected.
MAXLENGTH
constrains the number of characters that can be
entered into a text input field. If the value of
MAXLENGTH is greater the the value of the SIZE
attribute, the field should scroll appropriately.
The default number of characters is unlimited.
NAME
symbolic name for the form field corresponding to
this element or group of elements.
SIZE
specifies the amount of display space allocated to
this input field according to its type.
SRC
A URI specifying an image resource. For use only
with `TYPE=IMAGE'.
TYPE
indicates type of the field. Defaults to `TEXT'.
Values are:
CHECKBOX
an independent boolean value.
HIDDEN
a hidden field. The user does not interact with
this field; instead, the VALUE attribute can be
used to specify a value.
IMAGE
specifies an image resource to display, and allows
input of two form data: the x and y coordinate of
a pixel chosen from the image. The names of the
data are the name of this element with `.x' and
`.y' appended. `TYPE=IMAGE' implies `TYPE=SUBMIT'
processing; that is, when a pixel is chosen, the
form as a whole is submitted.
PASSWORD
Similar to the TEXT attribute, except that the
value is obscured as it is entered.
RADIO
a 1-of-many choice. All <INPUT> elements with
`TYPE=RADIO' and the same NAME combine into one
form field. The value of the form field is the
VALUE of the element chosen by the user. The
initial state may be indicated with the CHECKED
attribute. The VALUE attribute is required for
radio inputs.
RESET
an input option, typically a button, that
instructs the user agent to reset the form's
fields to their initial states. Any VALUE
attribute indicates a label for the input
(button).
SUBMIT
an input option, typically a button, that
instructs the user agent to submit the form. Any
VALUE attribute indicates a label for the input
(button). If the NAME attribute is present, this
element contributes a form field whose value is
given by the VALUE attribute. If the NAME
attribute is not present, this element does not
contribute a form field.
TEXT
a single line text entry fields. The SIZE and
MAXLENGTH attributes may be used to constrain the
input or layout of the field. Use the <TEXTAREA>
element for mulit-line text fields.
VALUE
The initial value of the field.
7.1.3. Selection: <SELECT>
The <SELECT> element constrains the form field to an
enumerated list of values. The values are given in <OPTION>
elements. Attributes are:
MULTIPLE
indicates that more than one option may be
included in the value.
NAME
specifies the name of the form field.
SIZE
specifies the number of visible items. Select
fields of size one are typically pop-down menus,
whereas select fields with size greater than one
are typically lists.
For example:
<SELECT NAME="flavor">
<OPTION>Vanilla
<OPTION>Strawberry
<OPTION>Rum and Raisin
<OPTION>Peach and Orange
</SELECT>
The initial state has the first option selected, unless a
SELECTED attribute is present on any of the <OPTION>
elements.
7.1.3.1. Option: <OPTION>
The Option element can only occur within a Select element.
It represents one choice, and has the following attributes:
SELECTED
Indicates that this option is initially selected.
VALUE
indicates the value to be returned if this option
is chosen. The field value defaults to the content
of the <OPTION> element.
The content of the <OPTION> element is presented to the user
to represent the option. It is used as a returned value if
the VALUE attribute is not present.
7.1.4. Text Area: <TEXTAREA>
The <TEXTAREA> element represents a multi-line text field.
For example:
<TEXTAREA NAME="address" ROWS=64 COLS=6>
HaL Computer Systems
1315 Dell Avenue
Campbell, California 95008
</TEXTAREA>
The content of the <TEXTAREA> element is the field's initial
value.
Typically, the ROWS and COLS attributes determine the
visible dimension of the field in characters. The field is
rendered in a fixed-width font. HTML user agents should
allow text to extend beyond these limits by scrolling as
needed.
7.2. Form Submission
An HTML user agent begins processing a form by presenting
the document with the fields in their initial state. The
user is allowed to modify the fields, constrained by the
field type etc. When the user indicates that the form should
be submitted (using a submit button or image input), the
form data set is processed according to its method, action
URI and enctype.
When there is only one single-line text input field in a
form, the user agent should accept Enter in that field as a
request to submit the form.
7.2.1. The `application/x-www-form-urlencoded' Media Type
The default encoding for all forms is
`application/x-www-form-urlencoded'. A form data set is
represented in this media type as follows:
1. The form field names and values are escaped: space
characterss are replaced by `+', and then reserved
characters are escaped as per [URL]; that is,
non-alphanumeric characters are replaced by `%HH', a
percent sign and two hexadecimal digits representing
the ASCII code of the character. Line breaks, as in
multi-line textfield values, are represented as CR LF
pairs, i.e. `%0D0A'.
2. The fields are listed in the order they appear in
the document with the name separated from the value by
`=' and the pairs separated from each other by `&'.
Fields with null values may be omitted. In particular,
unselected radio buttons and checkboxes should not
appear in the encoded data, but hidden fields with
VALUE attributes present should.
NOTE - The URI from a query form submission can be used
in a normal anchor style hyperlink. Unfortunately, the
use of the `&' character to separate form fields
interacts with its use in SGML attribute values as an
entity reference delimiter. For example, the URI
`http://host/?x=1&y=2' must be written `<a
href="http://host/?x=1&y=2"' or `<a
href="http://host/?x=1&#amp;y=2">'.
HTTP server implementors, and in particular, CGI
implementors are encouraged to support the use of `;'
in place of `&' to save users the trouble of escaping
`&' characters this way.
7.2.2. Query Forms: `METHOD=GET'
If the processing of a form is idempotent (i.e. it has no
lasting observable effect on the state of the world), then
the form method should be `GET'. Many database searches have
no visible side-effects and make ideal applications of query
forms.
To process a form whose action URL is an HTTP URL and whose
method is `GET', the user agent starts with the action URI
and appends a `?' and the form data set, in
`application/x-www-form-urlencoded' format as above. The
user agent then traverses the link to this URI just as if it
were an anchor (see 6.2, "Traversing Hyperlinks").
NOTE - The URL encoding may result in vary long URIs,
which cause some historical HTTP server implementations
to exhibit defective behavior. As a result, some HTML
forms are written using `METHOD=POST' even though the
form submission has no side-effects.
7.2.3. Forms with Side-Effects: `METHOD=POST'
If the service associated with the processing of a form has
side effects (for example, modification of a database or
subscription to a service), the method should be `POST'.
To process a form whose action URL is an HTTP URL and whose
method is `POST', the user agent conducts an HTTP POST
transaction using the action URI, and a message body of type
`application/x-www-form-urlencoded' format as above. The
user agent should display the response from the HTTP POST
interaction just as it would display the response from an
HTTP GET above.
7.2.4. Example Form Submission: Questionnaire Form
Consider the following document:
<title>Sample of HTML Form Submission</title>
<H1>Sample Questionnaire</H1>
<P>Please fill out this questionnaire:
<FORM METHOD="POST" ACTION="http://www.w3.org/sample">
<P>Your name: <INPUT NAME="name" size="48">
<P>Male <INPUT NAME="gender" TYPE=RADIO VALUE="male">
<P>Female <INPUT NAME="gender" TYPE=RADIO VALUE="female">
<P>Number in family: <INPUT NAME="family" TYPE=text>
<P>Cities in which you maintain a residence:
<UL>
<LI>Kent <INPUT NAME="city" TYPE=checkbox VALUE="kent">
<LI>Miami <INPUT NAME="city" TYPE=checkbox VALUE="miami">
<LI>Other <TEXTAREA NAME="other" cols=48 rows=4></textarea>
</UL>
Nickname: <INPUT NAME="nickname" SIZE="42">
<P>Thank you for responding to this questionnaire.
<P><INPUT TYPE=SUBMIT> <INPUT TYPE=RESET>
</FORM>
The inital state of the form data set is:
name
``''
gender
``male''
family
``''
other
``''
nickname
``''
Note that the radio input has an initial value, while the
checkbox has none.
The user might edit the fields and request that the form be
submitted. At that point, suppose the values are:
name
``John Doe''
gender
``male''
family
``5''
city
``kent,miami''
other
``abc\ndef''
nickname
``J&D''
The user agent then conducts an HTTP POST transaction using
the URI `http://www.w3.org/sample'. The message body would
be (ignore the linebreak):
name=John+Doe&gender=male&family=5&city=kent%2Cmiami&
other=abc%0D0Adef&nickname=J%26D
8. HTML Public Text
8.1. HTML DTD
This is the Document Type Definition for the HyperText
Markup Language.
<!-- html.dtd
Document Type Definition for the HyperText Markup Language
(HTML DTD)
$Id: html.dtd,v 1.25 1995/03/29 18:53:13 connolly Exp $
Author: Daniel W. Connolly <connolly@w3.org>
See Also: html.decl, html-0.dtd, html-1.dtd
http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html
-->
<!ENTITY % HTML.Version
"-//IETF//DTD HTML 2.0//EN"
-- Typical usage:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html>
...
</html>
--
>
<!--============ Feature Test Entities ========================-->
<!ENTITY % HTML.Recommended "IGNORE"
-- Certain features of the language are necessary for
compatibility with widespread usage, but they may
compromise the structural integrity of a document.
This feature test entity enables a more prescriptive
document type definition that eliminates
those features.
-->
<![ %HTML.Recommended [
<!ENTITY % HTML.Deprecated "IGNORE">
]]>
<!ENTITY % HTML.Deprecated "INCLUDE"
-- Certain features of the language are necessary for
compatibility with earlier versions of the specification,
but they tend to be used an implemented inconsistently,
and their use is deprecated. This feature test entity
enables a document type definition that eliminates
these features.
-->
<!ENTITY % HTML.Highlighting "INCLUDE"
-- Use this feature test entity to validate that a
document uses no highlighting tags, which may be
ignored on minimal implementations.
-->
<!ENTITY % HTML.Forms "INCLUDE"
-- Use this feature test entity to validate that a document
contains no forms, which may not be supported in minimal
implementations
-->
<!--============== Imported Names ==============================-->
<!ENTITY % Content-Type "CDATA"
-- meaning an internet media type
(aka MIME content type, as per RFC1521)
-->
<!ENTITY % HTTP-Method "GET | POST"
-- as per HTTP specification, in progress
-->
<!ENTITY % URI "CDATA"
-- The term URI means a CDATA attribute
whose value is a Uniform Resource Identifier,
as defined by
"Universal Resource Identifiers" by Tim Berners-Lee
aka RFC 1630
Note that CDATA attributes are limited by the LITLEN
capacity (1024 in the current version of html.decl),
so that URIs in HTML have a bounded length.
-->
<!--========= DTD "Macros" =====================-->
<!ENTITY % heading "H1|H2|H3|H4|H5|H6">
<!ENTITY % list " UL | OL | DIR | MENU " >
<!--======= Character mnemonic entities =================-->
<!ENTITY % ISOlat1 PUBLIC
"ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML">
%ISOlat1;
<!ENTITY amp CDATA "&" -- ampersand -->
<!ENTITY gt CDATA ">" -- greater than -->
<!ENTITY lt CDATA "<" -- less than -->
<!ENTITY quot CDATA """ -- double quote -->
<!--========= SGML Document Access (SDA) Parameter Entities =====-->
<!-- HTML 2.0 contains SGML Document Access (SDA) fixed attributes
in support of easy transformation to the International Committee
for Accessible Document Design (ICADD) DTD
"-//EC-USA-CDA/ICADD//DTD ICADD22//EN".
ICADD applications are designed to support usable access to
structured information by print-impaired individuals through
Braille, large print and voice synthesis. For more information on
SDA & ICADD:
- ISO 12083:1993, Annex A.8, Facilities for Braille,
large print and computer voice
- ICADD ListServ
<ICADD%ASUACAD.BITNET@ARIZVM1.ccit.arizona.edu>
- Usenet news group bit.listserv.easi
- Recording for the Blind, +1 800 221 4792
-->
<!ENTITY % SDAFORM "SDAFORM CDATA #FIXED"
-- one to one mapping -->
<!ENTITY % SDARULE "SDARULE CDATA #FIXED"
-- context-sensitive mapping -->
<!ENTITY % SDAPREF "SDAPREF CDATA #FIXED"
-- generated text prefix -->
<!ENTITY % SDASUFF "SDASUFF CDATA #FIXED"
-- generated text suffix -->
<!ENTITY % SDASUSP "SDASUSP NAME #FIXED"
-- suspend transform process -->
<!--========== Text Markup =====================-->
<![ %HTML.Highlighting [
<!ENTITY % font " TT | B | I ">
<!ENTITY % phrase "EM | STRONG | CODE | SAMP | KBD | VAR | CITE ">
<!ENTITY % text "#PCDATA | A | IMG | BR | %phrase | %font">
<!ELEMENT (%font;|%phrase) - - (%text)*>
<!ATTLIST ( TT | CODE | SAMP | KBD | VAR )
%SDAFORM; "Lit"
>
<!ATTLIST ( B | STRONG )
%SDAFORM; "B"
>
<!ATTLIST ( I | EM | CITE )
%SDAFORM; "It"
>
<!-- <TT> Typewriter text -->
<!-- <B> Bold text -->
<!-- <I> Italic text -->
<!-- <EM> Emphasized phrase -->
<!-- <STRONG> Strong emphais -->
<!-- <CODE> Source code phrase -->
<!-- <SAMP> Sample text or characters -->
<!-- <KBD> Keyboard phrase, e.g. user input -->
<!-- <VAR> Variable phrase or substituable -->
<!-- <CITE> Name or title of cited work -->
<!ENTITY % pre.content "#PCDATA | A | HR | BR | %font | %phrase">
]]>
<!ENTITY % text "#PCDATA | A | IMG | BR">
<!ELEMENT BR - O EMPTY>
<!ATTLIST BR
%SDAPREF; "&#RE;"
>
<!-- <BR> Line break -->
<!--========= Link Markup ======================-->
<![ %HTML.Recommended [
<!ENTITY % linkName "ID">
]]>
<!ENTITY % linkName "CDATA">
<!ENTITY % linkType "NAME"
-- a list of these will be specified at a later date -->
<!ENTITY % linkExtraAttributes
"REL %linkType #IMPLIED
REV %linkType #IMPLIED
URN CDATA #IMPLIED
TITLE CDATA #IMPLIED
METHODS NAMES #IMPLIED
">
<![ %HTML.Recommended [
<!ENTITY % A.content "(%text)*"
-- <H1><a name="xxx">Heading</a></H1>
is preferred to
<a name="xxx"><H1>Heading</H1></a>
-->
]]>
<!ENTITY % A.content "(%heading|%text)*">
<!ELEMENT A - - %A.content -(A)>
<!ATTLIST A
HREF %URI #IMPLIED
NAME %linkName #IMPLIED
%linkExtraAttributes;
%SDAPREF; "<Anchor: #AttList>"
>
<!-- <A> Anchor; source/destination of link -->
<!-- <A NAME="..."> Name of this anchor -->
<!-- <A HREF="..."> Address of link destination -->
<!-- <A URN="..."> Permanent address of destination -->
<!-- <A REL=...> Relationship to destination -->
<!-- <A REV=...> Relationship of destination to this -->
<!-- <A TITLE="..."> Title of destination (advisory) -->
<!-- <A METHODS="..."> Operations on destination (advisory) -->
<!--========== Images ==========================-->
<!ELEMENT IMG - O EMPTY>
<!ATTLIST IMG
SRC %URI; #REQUIRED
ALT CDATA #IMPLIED
ALIGN (top|middle|bottom) #IMPLIED
ISMAP (ISMAP) #IMPLIED
%SDAPREF; "<Fig><?SDATrans Img: #AttList>#AttVal(Alt)</Fig>"
>
<!-- <IMG> Image; icon, glyph or illustration -->
<!-- <IMG SRC="..."> Address of image object -->
<!-- <IMG ALT="..."> Textual alternative -->
<!-- <IMG ALIGN=...> Position relative to text -->
<!-- <IMG ISMAP> Each pixel can be a link -->
<!--========== Paragraphs=======================-->
<!ELEMENT P - O (%text)*>
<!ATTLIST P
%SDAFORM; "Para"
>
<!-- <P> Paragraph -->
<!--========== Headings, Titles, Sections ===============-->
<!ELEMENT HR - O EMPTY>
<!ATTLIST HR
%SDAPREF; "&#RE;&#RE;"
>
<!-- <HR> Horizontal rule -->
<!ELEMENT ( %heading ) - - (%text;)*>
<!ATTLIST H1
%SDAFORM; "H1"
>
<!ATTLIST H2
%SDAFORM; "H2"
>
<!ATTLIST H3
%SDAFORM; "H3"
>
<!ATTLIST H4
%SDAFORM; "H4"
>
<!ATTLIST H5
%SDAFORM; "H5"
>
<!ATTLIST H6
%SDAFORM; "H6"
>
<!-- <H1> Heading, level 1 -->
<!-- <H2> Heading, level 2 -->
<!-- <H3> Heading, level 3 -->
<!-- <H4> Heading, level 4 -->
<!-- <H5> Heading, level 5 -->
<!-- <H6> Heading, level 6 -->
<!--========== Text Flows ======================-->
<![ %HTML.Forms [
<!ENTITY % block.forms "BLOCKQUOTE | FORM | ISINDEX">
]]>
<!ENTITY % block.forms "BLOCKQUOTE">
<![ %HTML.Deprecated [
<!ENTITY % preformatted "PRE | XMP | LISTING">
]]>
<!ENTITY % preformatted "PRE">
<!ENTITY % block "P | %list | DL
| %preformatted
| %block.forms">
<!ENTITY % flow "(%text|%block)*">
<!ENTITY % pre.content "#PCDATA | A | HR | BR">
<!ELEMENT PRE - - (%pre.content)*>
<!ATTLIST PRE
WIDTH NUMBER #implied
%SDAFORM; "Lit"
>
<!-- <PRE> Preformatted text -->
<!-- <PRE WIDTH=...> Maximum characters per line -->
<![ %HTML.Deprecated [
<!ENTITY % literal "CDATA"
-- historical, non-conforming parsing mode where
the only markup signal is the end tag
in full
-->
<!ELEMENT (XMP|LISTING) - - %literal>
<!ATTLIST XMP
%SDAFORM; "Lit"
%SDAPREF; "Example:&#RE;"
>
<!ATTLIST LISTING
%SDAFORM; "Lit"
%SDAPREF; "Listing:&#RE;"
>
<!-- <XMP> Example section -->
<!-- <LISTING> Computer listing -->
<!ELEMENT PLAINTEXT - O %literal>
<!-- <PLAINTEXT> Plain text passage -->
<!ATTLIST PLAINTEXT
%SDAFORM; "Lit"
>
]]>
<!--========== Lists ==================-->
<!ELEMENT DL - - (DT | DD)+>
<!ATTLIST DL
COMPACT (COMPACT) #IMPLIED
%SDAFORM; "List"
%SDAPREF; "Definition List:"
>
<!ELEMENT DT - O (%text)*>
<!ATTLIST DT
%SDAFORM; "Term"
>
<!ELEMENT DD - O %flow>
<!ATTLIST DD
%SDAFORM; "LItem"
>
<!-- <DL> Definition list, or glossary -->
<!-- <DL COMPACT> Compact style list -->
<!-- <DT> Term in definition list -->
<!-- <DD> Definition of term -->
<!ELEMENT (OL|UL) - - (LI)+>
<!ATTLIST OL
COMPACT (COMPACT) #IMPLIED
%SDAFORM; "List"
>
<!ATTLIST UL
COMPACT (COMPACT) #IMPLIED
%SDAFORM; "List"
>
<!-- <UL> Unordered list -->
<!-- <UL COMPACT> Compact list style -->
<!-- <OL> Ordered, or numbered list -->
<!-- <OL COMPACT> Compact list style -->
<!ELEMENT (DIR|MENU) - - (LI)+ -(%block)>
<!ATTLIST DIR
COMPACT (COMPACT) #IMPLIED
%SDAFORM; "List"
%SDAPREF; "<LHead>Directory</LHead>"
>
<!ATTLIST MENU
COMPACT (COMPACT) #IMPLIED
%SDAFORM; "List"
%SDAPREF; "<LHead>Menu</LHead>"
>
<!-- <DIR> Directory list -->
<!-- <DIR COMPACT> Compact list style -->
<!-- <MENU> Menu list -->
<!-- <MENU COMPACT> Compact list style -->
<!ELEMENT LI - O %flow>
<!ATTLIST LI
%SDAFORM; "LItem"
>
<!-- <LI> List item -->
<!--========== Document Body ===================-->
<![ %HTML.Recommended [
<!ENTITY % body.content "(%heading|%block|HR|ADDRESS|IMG)*"
-- <h1>Heading</h1>
<p>Text ...
is preferred to
<h1>Heading</h1>
Text ...
-->
]]>
<!ENTITY % body.content "(%heading | %text | %block |
HR | ADDRESS)*">
<!ELEMENT BODY O O %body.content>
<!-- <BODY> Document body -->
<!ELEMENT BLOCKQUOTE - - %body.content>
<!ATTLIST BLOCKQUOTE
%SDAFORM; "BQ"
>
<!-- <BLOCKQUOTE> Quoted passage -->
<!ELEMENT ADDRESS - - (%text|P)*>
<!ATTLIST ADDRESS
%SDAFORM; "Lit"
%SDAPREF; "Address:&#RE;"
>
<!-- <ADDRESS> Address, signature, or byline -->
<!--======= Forms ====================-->
<![ %HTML.Forms [
<!ELEMENT FORM - - %body.content -(FORM) +(INPUT|SELECT|TEXTAREA)>
<!ATTLIST FORM
ACTION %URI #IMPLIED
METHOD (%HTTP-Method) GET
ENCTYPE %Content-Type; "application/x-www-form-urlencoded"
%SDAPREF; "<Para>Form:</Para>"
%SDASUFF; "<Para>Form End.</Para>"
>
<!-- <FORM> Fill-out or data-entry form -->
<!-- <FORM ACTION="..."> Address for completed form -->
<!-- <FORM METHOD=...> Method of submitting form -->
<!-- <FORM ENCTYPE="..."> Representation of form data -->
<!ENTITY % InputType "(TEXT | PASSWORD | CHECKBOX |
RADIO | SUBMIT | RESET |
IMAGE | HIDDEN )">
<!ELEMENT INPUT - O EMPTY>
<!ATTLIST INPUT
TYPE %InputType TEXT
NAME CDATA #IMPLIED
VALUE CDATA #IMPLIED
SRC %URI #IMPLIED
CHECKED (CHECKED) #IMPLIED
SIZE CDATA #IMPLIED
MAXLENGTH NUMBER #IMPLIED
ALIGN (top|middle|bottom) #IMPLIED
%SDAPREF; "Input: "
>
<!-- <INPUT> Form input datum -->
<!-- <INPUT TYPE=...> Type of input interaction -->
<!-- <INPUT NAME=...> Name of form datum -->
<!-- <INPUT VALUE="..."> Default/initial/selected value -->
<!-- <INPUT SRC="..."> Address of image -->
<!-- <INPUT CHECKED> Initial state is "on" -->
<!-- <INPUT SIZE=...> Field size hint -->
<!-- <INPUT MAXLENGTH=...> Data length maximum -->
<!-- <INPUT ALIGN=...> Image alignment -->
<!ELEMENT SELECT - - (OPTION+) -(INPUT|SELECT|TEXTAREA)>
<!ATTLIST SELECT
NAME CDATA #REQUIRED
SIZE NUMBER #IMPLIED
MULTIPLE (MULTIPLE) #IMPLIED
%SDAFORM; "List"
%SDAPREF;
"<LHead>Select #AttVal(Multiple)</LHead>"
>
<!-- <SELECT> Selection of option(s) -->
<!-- <SELECT NAME=...> Name of form datum -->
<!-- <SELECT SIZE=...> Options displayed at a time -->
<!-- <SELECT MULTIPLE> Multiple selections allowed -->
<!ELEMENT OPTION - O (#PCDATA)*>
<!ATTLIST OPTION
SELECTED (SELECTED) #IMPLIED
VALUE CDATA #IMPLIED
%SDAFORM; "LItem"
%SDAPREF;
"Option: #AttVal(Value) #AttVal(Selected)"
>
<!-- <OPTION> A selection option -->
<!-- <OPTION SELECTED> Initial state -->
<!-- <OPTION VALUE="..."> Form datum value for this option-->
<!ELEMENT TEXTAREA - - (#PCDATA)* -(INPUT|SELECT|TEXTAREA)>
<!ATTLIST TEXTAREA
NAME CDATA #REQUIRED
ROWS NUMBER #REQUIRED
COLS NUMBER #REQUIRED
%SDAFORM; "Para"
%SDAPREF; "Input Text -- #AttVal(Name): "
>
<!-- <TEXTAREA> An area for text input -->
<!-- <TEXTAREA NAME=...> Name of form datum -->
<!-- <TEXTAREA ROWS=...> Height of area -->
<!-- <TEXTAREA COLS=...> Width of area -->
]]>
<!--======= Document Head ======================-->
<![ %HTML.Recommended [
<!ENTITY % head.extra "META* & LINK*">
]]>
<!ENTITY % head.extra "NEXTID? & META* & LINK*">
<!ENTITY % head.content "TITLE & ISINDEX? & BASE? &
(%head.extra)">
<!ELEMENT HEAD O O (%head.content)>
<!-- <HEAD> Document head -->
<!ELEMENT TITLE - - (#PCDATA)*>
<!ATTLIST TITLE
%SDAFORM; "Ti" >
<!-- <TITLE> Title of document -->
<!ELEMENT LINK - O EMPTY>
<!ATTLIST LINK
HREF %URI #REQUIRED
%linkExtraAttributes;
%SDAPREF; "Linked to : #AttVal (TITLE) (URN) (HREF)>" >
<!-- <LINK> Link from this document -->
<!-- <LINK HREF="..."> Address of link destination -->
<!-- <LINK URN="..."> Lasting name of destination -->
<!-- <LINK REL=...> Relationship to destination -->
<!-- <LINK REV=...> Relationship of destination to this -->
<!-- <LINK TITLE="..."> Title of destination (advisory) -->
<!-- <LINK METHODS="..."> Operations allowed (advisory) -->
<!ELEMENT ISINDEX - O EMPTY>
<!ATTLIST ISINDEX
%SDAPREF;
"<Para>[Document is indexed/searchable.]</Para>">
<!-- <ISINDEX> Document is a searchable index -->
<!ELEMENT BASE - O EMPTY>
<!ATTLIST BASE
HREF %URI; #REQUIRED >
<!-- <BASE> Base context document -->
<!-- <BASE HREF="..."> Address for this document -->
<!ELEMENT NEXTID - O EMPTY>
<!ATTLIST NEXTID
N %linkName #REQUIRED >
<!-- <NEXTID> Next ID to use for link name -->
<!-- <NEXTID N=...> Next ID to use for link name -->
<!ELEMENT META - O EMPTY>
<!ATTLIST META
HTTP-EQUIV NAME #IMPLIED
NAME NAME #IMPLIED
CONTENT CDATA #REQUIRED >
<!-- <META> Generic Metainformation -->
<!-- <META HTTP-EQUIV=...> HTTP response header name -->
<!-- <META NAME=...> Metainformation name -->
<!-- <META CONTENT="..."> Associated information -->
<!--======= Document Structure =================-->
<![ %HTML.Deprecated [
<!ENTITY % html.content "HEAD, BODY, PLAINTEXT?">
]]>
<!ENTITY % html.content "HEAD, BODY">
<!ELEMENT HTML O O (%html.content)>
<!ENTITY % version.attr "VERSION CDATA #FIXED '%HTML.Version;'">
<!ATTLIST HTML
%version.attr;
%SDAFORM; "Book"
>
<!-- <HTML> HTML Document -->
8.2. SGML Declaration for HTML
This is the SGML Declaration for HyperText Markup Language
(HTML) as used by the World Wide Web (WWW) application:
<!SGML "ISO 8879:1986"
--
SGML Declaration for HyperText Markup Language (HTML).
--
CHARSET
BASESET "ISO 646:1983//CHARSET
International Reference Version
(IRV)//ESC 2/5 4/0"
DESCSET 0 9 UNUSED
9 2 9
11 2 UNUSED
13 1 13
14 18 UNUSED
32 95 32
127 1 UNUSED
BASESET "ISO Registration Number 100//CHARSET
ECMA-94 Right Part of
Latin Alphabet Nr. 1//ESC 2/13 4/1"
DESCSET 128 32 UNUSED
160 96 32
CAPACITY SGMLREF
TOTALCAP 150000
GRPCAP 150000
ENTCAP 150000
SCOPE DOCUMENT
SYNTAX
SHUNCHAR CONTROLS 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 127
BASESET "ISO 646:1983//CHARSET
International Reference Version
(IRV)//ESC 2/5 4/0"
DESCSET 0 128 0
FUNCTION
RE 13
RS 10
SPACE 32
TAB SEPCHAR 9
NAMING LCNMSTRT ""
UCNMSTRT ""
LCNMCHAR ".-"
UCNMCHAR ".-"
NAMECASE GENERAL YES
ENTITY NO
DELIM GENERAL SGMLREF
SHORTREF SGMLREF
NAMES SGMLREF
QUANTITY SGMLREF
ATTSPLEN 2100
LITLEN 1024
NAMELEN 72 -- somewhat arbitrary; taken from
internet line length conventions --
PILEN 1024
TAGLEN 2100
GRPGTCNT 150
GRPCNT 64
FEATURES
MINIMIZE
DATATAG NO
OMITTAG YES
RANK NO
SHORTTAG YES
LINK
SIMPLE NO
IMPLICIT NO
EXPLICIT NO
OTHER
CONCUR NO
SUBDOC NO
FORMAL YES
APPINFO "SDA" -- conforming SGML Document Access application
--
>
<!--
$Id: html.decl,v 1.15 1995/05/06 01:44:47 connolly Exp $
Author: Daniel W. Connolly <connolly@hal.com>
See also: http://www.hal.com/%7Econnolly/html-spec
http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html
-->
8.3. Sample SGML Open Entity Catalog for HTML
The SGML standard describes an ``entity manager'' as the
portion or component of an SGML system that maps SGML
entities into the actual storage model (e.g., the file
system). The standard itself does not define a particular
mapping methodology or notation.
To assist the interoperability among various SGML tools and
systems, the SGML Open consortium has passed a technical
resolution that defines a format for an application-
independent entity catalog that maps external identifiers
and/or entity names to file names.
Each entry in the catalog associates a storage object
identifier (such as a file name) with information about the
external entity that appears in the SGML document. In
addition to entries that associate public identifiers, a
catalog entry can associate an entity name with a storage
object indentifier. For example, the following are possible
catalog entries:
-- catalog: SGML Open style entity catalog for HTML --
-- $Id: catalog,v 1.2 1994/11/30 23:45:18 connolly Exp $ --
-- Ways to refer to Level 2: most general to most specific --
PUBLIC "-//IETF//DTD HTML//EN" html.dtd
PUBLIC "-//IETF//DTD HTML 2.0//EN" html.dtd
PUBLIC "-//IETF//DTD HTML Level 2//EN" html.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Level 2//EN" html.dtd
-- Ways to refer to Level 1: most general to most specific --
PUBLIC "-//IETF//DTD HTML Level 1//EN" html-1.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN" html-1.dtd
-- Ways to refer to Level 0: most general to most specific --
PUBLIC "-//IETF//DTD HTML Level 0//EN" html-0.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Level 0//EN" html-0.dtd
-- Ways to refer to Strict Level 2: most general to most specific --
PUBLIC "-//IETF//DTD HTML Strict//EN" html-s.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Strict//EN" html-s.dtd
PUBLIC "-//IETF//DTD HTML Strict Level 2//EN" html-s.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 2//EN" html-s.dtd
-- Ways to refer to Strict Level 1: most general to most specific --
PUBLIC "-//IETF//DTD HTML Strict Level 1//EN" html-1s.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 1//EN" html-1s.dtd
-- Ways to refer to Strict Level 0: most general to most specific --
PUBLIC "-//IETF//DTD HTML Strict Level 0//EN" html-0s.dtd
PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 0//EN" html-0s.dtd
-- ISO latin 1 entity set for HTML --
PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML" ISOlat1.sgml
8.4. Character Entity Sets
The HTML DTD defines the following entities. They represent
particular graphic characters which have special meanings in
places in the markup, or may not be part of the character
set available to the writer.
8.4.1. Numeric and Special Graphic Entity Set
The following table lists each of the characters included
from the Numeric and Special Graphic entity set, along with
its name, syntax for use, and description. This list is
derived from `ISO Standard 8879:1986//ENTITIES Numeric and
Special Graphic//EN'. However, HTML does not include for the
entire entity set -- only the entities listed below are
included.
GLYPH NAME SYNTAX DESCRIPTION
< lt < Less than sign
> gt > Greater than sign
& amp & Ampersand
" quot " Double quote sign
8.4.2. ISO Latin 1 Character Entity Set
The following public text lists each of the characters
specified in the Added Latin 1 entity set, along with its
name, syntax for use, and description. This list is derived
from ISO Standard 8879:1986//ENTITIES Added Latin 1//EN.
HTML includes the entire entity set.
<!-- (C) International Organization for Standardization 1986
Permission to copy in any form is granted for use with
conforming SGML systems and applications as defined in
ISO 8879, provided this notice is included in all copies.
-->
<!-- Character entity set. Typical invocation:
<!ENTITY % ISOlat1 PUBLIC
"ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML">
%ISOlat1;
-->
<!-- Modified for use in HTML
$Id: ISOlat1.sgml,v 1.2 1994/11/30 23:45:12 connolly Exp $ -->
<!ENTITY AElig CDATA "Æ" -- capital AE diphthong (ligature) -->
<!ENTITY Aacute CDATA "Á" -- capital A, acute accent -->
<!ENTITY Acirc CDATA "Â" -- capital A, circumflex accent -->
<!ENTITY Agrave CDATA "À" -- capital A, grave accent -->
<!ENTITY Aring CDATA "Å" -- capital A, ring -->
<!ENTITY Atilde CDATA "Ã" -- capital A, tilde -->
<!ENTITY Auml CDATA "Ä" -- capital A, dieresis or umlaut mark -->
<!ENTITY Ccedil CDATA "Ç" -- capital C, cedilla -->
<!ENTITY ETH CDATA "Ð" -- capital Eth, Icelandic -->
<!ENTITY Eacute CDATA "É" -- capital E, acute accent -->
<!ENTITY Ecirc CDATA "Ê" -- capital E, circumflex accent -->
<!ENTITY Egrave CDATA "È" -- capital E, grave accent -->
<!ENTITY Euml CDATA "Ë" -- capital E, dieresis or umlaut mark -->
<!ENTITY Iacute CDATA "Í" -- capital I, acute accent -->
<!ENTITY Icirc CDATA "Î" -- capital I, circumflex accent -->
<!ENTITY Igrave CDATA "Ì" -- capital I, grave accent -->
<!ENTITY Iuml CDATA "Ï" -- capital I, dieresis or umlaut mark -->
<!ENTITY Ntilde CDATA "Ñ" -- capital N, tilde -->
<!ENTITY Oacute CDATA "Ó" -- capital O, acute accent -->
<!ENTITY Ocirc CDATA "Ô" -- capital O, circumflex accent -->
<!ENTITY Ograve CDATA "Ò" -- capital O, grave accent -->
<!ENTITY Oslash CDATA "Ø" -- capital O, slash -->
<!ENTITY Otilde CDATA "Õ" -- capital O, tilde -->
<!ENTITY Ouml CDATA "Ö" -- capital O, dieresis or umlaut mark -->
<!ENTITY THORN CDATA "Þ" -- capital THORN, Icelandic -->
<!ENTITY Uacute CDATA "Ú" -- capital U, acute accent -->
<!ENTITY Ucirc CDATA "Û" -- capital U, circumflex accent -->
<!ENTITY Ugrave CDATA "Ù" -- capital U, grave accent -->
<!ENTITY Uuml CDATA "Ü" -- capital U, dieresis or umlaut mark -->
<!ENTITY Yacute CDATA "Ý" -- capital Y, acute accent -->
<!ENTITY aacute CDATA "á" -- small a, acute accent -->
<!ENTITY acirc CDATA "â" -- small a, circumflex accent -->
<!ENTITY aelig CDATA "æ" -- small ae diphthong (ligature) -->
<!ENTITY agrave CDATA "à" -- small a, grave accent -->
<!ENTITY aring CDATA "å" -- small a, ring -->
<!ENTITY atilde CDATA "ã" -- small a, tilde -->
<!ENTITY auml CDATA "ä" -- small a, dieresis or umlaut mark -->
<!ENTITY ccedil CDATA "ç" -- small c, cedilla -->
<!ENTITY eacute CDATA "é" -- small e, acute accent -->
<!ENTITY ecirc CDATA "ê" -- small e, circumflex accent -->
<!ENTITY egrave CDATA "è" -- small e, grave accent -->
<!ENTITY eth CDATA "ð" -- small eth, Icelandic -->
<!ENTITY euml CDATA "ë" -- small e, dieresis or umlaut mark -->
<!ENTITY iacute CDATA "í" -- small i, acute accent -->
<!ENTITY icirc CDATA "î" -- small i, circumflex accent -->
<!ENTITY igrave CDATA "ì" -- small i, grave accent -->
<!ENTITY iuml CDATA "ï" -- small i, dieresis or umlaut mark -->
<!ENTITY ntilde CDATA "ñ" -- small n, tilde -->
<!ENTITY oacute CDATA "ó" -- small o, acute accent -->
<!ENTITY ocirc CDATA "ô" -- small o, circumflex accent -->
<!ENTITY ograve CDATA "ò" -- small o, grave accent -->
<!ENTITY oslash CDATA "ø" -- small o, slash -->
<!ENTITY otilde CDATA "õ" -- small o, tilde -->
<!ENTITY ouml CDATA "ö" -- small o, dieresis or umlaut mark -->
<!ENTITY szlig CDATA "ß" -- small sharp s, German (sz ligature) -->
<!ENTITY thorn CDATA "þ" -- small thorn, Icelandic -->
<!ENTITY uacute CDATA "ú" -- small u, acute accent -->
<!ENTITY ucirc CDATA "û" -- small u, circumflex accent -->
<!ENTITY ugrave CDATA "ù" -- small u, grave accent -->
<!ENTITY uuml CDATA "ü" -- small u, dieresis or umlaut mark -->
<!ENTITY yacute CDATA "ý" -- small y, acute accent -->
<!ENTITY yuml CDATA "ÿ" -- small y, dieresis or umlaut mark -->
9. Glossary
absolute URI
a URI in absolute form, as per [URL]
anchor
a hyperlink navigation option; typically, a
highlighted phrase marked as an <A> element.
base URI
URI used as the base of an HTML document for the
purpose of resolving hyperlink destinations.
character
An atom of information, for example a letter or a
digit. Graphic characters have associated glyphs,
where as control characters have associated
processing semantics.
character
encoding scheme
A function whose domain is the set of sequences of
octets, and whose range is the set of sequences of
characters from a character repertoire; that is, a
sequence of octets and a character encoding scheme
determines a sequence of characters.
character
repertoire
A finite set of characters; e.g. the range of a
coded character set.
code position
An integer. A coded character set and a code
position from its domain determine a character.
coded character
set
A function whose domain is a subset of the
integers and whose range is a character
repertoire. That is, for some set of integers
(usually of the form {0, 1, 2, ..., N} ), a coded
character set and an integer in that set determine
a character. Conversely, a character and a coded
character set determine the character's code
position (or, in rare cases, a few code
positions).
conforming HTML
user agent
A user agent that conforms to this specification
in its processing of the Internet Media Type
`text/html; version=2.0'.
data character
Characters other than markup, which make up the
content of elements.
document
character set
a coded character set whose range includes all
characters used in a document. Every SGML document
has exactly one document character set. Numeric
character references are resolved via the document
character set.
DTD
document type definition. Rules that apply SGML to
the markup of documents of a particular type,
including a set of element and entity
declarations. [SGML]
element
A component of the hierarchical structure defined
by a document type definition; it is identified in
a document instance by descriptive markup, sually
a start-tag and end-tag. [SGML]
end-tag
Descriptive markup that identifies the end of an
element. [SGML]
entity
data with an associated notation or
interpretation; for example, a sequence of octets
associated with an Internet Media Type.[SGML]
fragment
identifier
the portion of an HREF attribute value following
the `#' character which modifies the prenentation
of the destination of a hyperlink.
form data set
a sequence of name/value pairs; the names are
given by an HTML document and the values are given
by a user.
HTML document
An SGML document conforming to this document type
definition.
hyperlink
a relationship between to resources, called the
source and the destination.
markup
Syntactically delimited characters added to the
data of a document to represent its structure.
There are four different kinds of markup:
descriptive markup (tags), references, markup
declarations, and processing instructions.[SGML]
may
A document or user interface is conforming whether
this statement applies or not.
media type
an Internet Media Type, as per [IMEDIA].
message entity
a head and body. The head is a collection of
name/value fields, and the body is a sequence of
octets. The head defines the content type and
content transfer encoding of the body. [MIME]
minimally
conforming HTML
user agent
A user agent that conforms to this specification
except for form processing. It may only process
level 1 HTML documents.
must
Documents or user agents in conflict with this
statement are not conforming.
SGML document
A sequence of characters organized physically as a
set of entities and logically into a hierarchy of
elements. An SGML document consists of data
characters and markup; the markup describes the
structure of the information and an instance of
that structure.[SGML]
shall
If a document or user agent conflicts with this
statement, it does not conform to this
specification.
should
If a document or user agent conflicts with this
statement, undesirable results may occur in
practice even though it conforms to this
specification.
start-tag
Descriptive markup that identifies the start of an
element and specifies its generic identifier and
attributes. [SGML]
syntax-reference
character set
A coded character set whose range includes all
characters used for markup; e.g. name characters
and delimiter characters.
tag
Markup that delimits an element. A tag includes a
name which refers to an element declaration in the
DTD, and may include attributes.[SGML]
text entity
A finite sequence of characters. A text entity
typically takes the form of a sequence of octets
with some associated character encoding scheme,
transmitted over the network or stored in a
file.[SGML]
typical
Typical processing is described for many elements.
This is not a mandatory part of the specification
but is given as guidance for designers and to help
explain the uses for which the elements were
intended.
URI
A Universal Resource Identifier is a formatted
string that serves as an identifier for a
resource, typcally on the Internet. URIs are used
in HTML to identify the destination of hyperlinks.
URIs in common practice include Uniform Resource
Locators (URLs)[URL] and Relative URLs[RELURL].
user agent
A component of a distributed system that presents
an interface and processes requests on behalf of a
user; for example, a www browser or a mail user
agent.
WWW
The World-Wide Web is a hypertext-based,
distributed information system created by
researchers at CERN in Switzerland. Users may
create, edit or browse hypertext documents.
`http://www.w3.org/'
10. Bibliography
[URI]
T. Berners-Lee. ``Universal Resource Identifiers
in WWW: A Unifying Syntax for the Expression of
Names and Addresses of Objects on the Network as
used in the World- Wide Web.'' RFC 1630, CERN,
June 1994.
[URL]
T. Berners-Lee, L. Masinter, and M. McCahill.
``Uniform Resource Locators (URL).'' RFC 1738,
CERN, Xerox PARC, University of Minnesota, October
1994.
[HTTP]
T. Berners-Lee, R. T. Fielding, and H. Frystyk
Nielsen. ``Hypertext Transfer Protocol -
HTTP/1.0.'' Work in Progress
(draft-ietf-http-v10-spec-00.ps), MIT, UC Irvine,
CERN, March 1995.
[MIME]
N. Borenstein and N. Freed. ``MIME (Multipurpose
Internet Mail Extensions) Part One: Mechanisms for
Specifying and Describing the Format of Internet
Message Bodies.'' RFC 1521, Bellcore, Innosoft,
September 1993.
[RELURL]
R. T. Fielding. ``Relative Uniform Resource
Locators.'' Work in Progress
(draft-ietf-uri-relative-url-06.txt), UC Irvine,
March 1995.
[GOLD90]
C. F. Goldfarb. ``The SGML Handbook.'' Y.
Rubinsky, Ed., Oxford University Press, 1990.
[IMEDIA]
J. Postel. ``Media Type Registration Procedure.''
RFC 1590, USC/ISI, March 1994.
[IANA]
J. Reynolds and J. Postel. ``Assigned Numbers.''
STD 2, RFC 1700, USC/ISI, October 1994.
[SQ91]
SoftQuad. ``The SGML Primer.'' 3rd ed., SoftQuad
Inc., 1991.
[US-ASCII]
US-ASCII. Coded Character Set - 7-Bit American
Standard Code for Information Interchange.
Standard ANSI X3.4-1986, ANSI, 1986.
[ISO-8859-1]
ISO 8859. International Standard -- Information
Processing -- 8-bit Single-Byte Coded Graphic
Character Sets -- Part 1: Latin Alphabet No. 1,
ISO 8859-1:1987. Part 2: Latin alphabet No. 2, ISO
8859-2, 1987. Part 3: Latin alphabet No. 3, ISO
8859-3, 1988. Part 4: Latin alphabet No. 4, ISO
8859-4, 1988. Part 5: Latin/Cyrillic alphabet, ISO
8859-5, 1988. Part 6: Latin/Arabic alphabet, ISO
8859-6, 1987. Part 7: Latin/Greek alphabet, ISO
8859-7, 1987. Part 8: Latin/Hebrew alphabet, ISO
8859-8, 1988. Part 9: Latin alphabet No. 5, ISO
8859-9, 1990.
[SGML]
ISO 8879. Information Processing - Text and Office
Systems - Standard Generalized Markup Language
(SGML), 1986.
11. Appendices
These appendices are provided for informational reasons only
- they do not form a part of the HTML specification.
11.1. The ANSI/ISO 8859-1 Coded Character Set
This list, sorted numerically, is derived from ANSI/ISO
8859-1 8-bit single-byte coded graphic character set:
REFERENCE DESCRIPTION
� - Unused
Horizontal tab
Line feed
- Unused
Space
! Exclamation mark
" Quotation mark
# Number sign
$ Dollar sign
% Percent sign
& Ampersand
' Apostrophe
( Left parenthesis
) Right parenthesis
* Asterisk
+ Plus sign
, Comma
- Hyphen
. Period (fullstop)
/ Solidus (slash)
0 - 9 Digits 0-9
: Colon
; Semi-colon
< Less than
= Equals sign
> Greater than
? Question mark
@ Commercial at
A - Z Letters A-Z
[ Left square bracket
\ Reverse solidus (backslash)
] Right square bracket
^ Caret
_ Horizontal bar (underscore)
` Acute accent
a - z Letters a-z
{ Left curly brace
| Vertical bar
} Right curly brace
~ Tilde
- Unused
¡ Inverted exclamation
¢ Cent sign
£ Pound sterling
¤ General currency sign
¥ Yen sign
¦ Broken vertical bar
§ Section sign
¨ Umlaut (dieresis)
© Copyright
ª Feminine ordinal
« Left angle quote, guillemotleft
¬ Not sign
Soft hyphen
® Registered trademark
¯ Macron accent
° Degree sign
± Plus or minus
² Superscript two
³ Superscript three
´ Acute accent
µ Micro sign
¶ Paragraph sign
· Middle dot
¸ Cedilla
¹ Superscript one
º Masculine ordinal
» Right angle quote, guillemotright
¼ Fraction one-fourth
½ Fraction one-half
¾ Fraction three-fourths
¿ Inverted question mark
À Capital A, grave accent
Á Capital A, acute accent
 Capital A, circumflex accent
à Capital A, tilde
Ä Capital A, dieresis or umlaut mark
Å Capital A, ring
Æ Capital AE dipthong (ligature)
Ç Capital C, cedilla
È Capital E, grave accent
É Capital E, acute accent
Ê Capital E, circumflex accent
Ë Capital E, dieresis or umlaut mark
Ì Capital I, grave accent
Í Capital I, acute accent
Î Capital I, circumflex accent
Ï Capital I, dieresis or umlaut mark
Ð Capital Eth, Icelandic
Ñ Capital N, tilde
Ò Capital O, grave accent
Ó Capital O, acute accent
Ô Capital O, circumflex accent
Õ Capital O, tilde
Ö Capital O, dieresis or umlaut mark
× Multiply sign
Ø Capital O, slash
Ù Capital U, grave accent
Ú Capital U, acute accent
Û Capital U, circumflex accent
Ü Capital U, dieresis or umlaut mark
Ý Capital Y, acute accent
Þ Capital THORN, Icelandic
ß Small sharp s, German (sz ligature)
à Small a, grave accent
á Small a, acute accent
â Small a, circumflex accent
ã Small a, tilde
ä Small a, dieresis or umlaut mark
å Small a, ring
æ Small ae dipthong (ligature)
ç Small c, cedilla
è Small e, grave accent
é Small e, acute accent
ê Small e, circumflex accent
ë Small e, dieresis or umlaut mark
ì Small i, grave accent
í Small i, acute accent
î Small i, circumflex accent
ï Small i, dieresis or umlaut mark
ð Small eth, Icelandic
ñ Small n, tilde
ò Small o, grave accent
ó Small o, acute accent
ô Small o, circumflex accent
õ Small o, tilde
ö Small o, dieresis or umlaut mark
÷ Division sign
ø Small o, slash
ù Small u, grave accent
ú Small u, acute accent
û Small u, circumflex accent
ü Small u, dieresis or umlaut mark
ý Small y, acute accent
þ Small thorn, Icelandic
ÿ Small y, dieresis or umlaut mark
11.2. Obsolete Features
This section describes elements that are no longer part of
HTML. Client implementors should implement these obsolete
elements for compatibility with previous versions of the
HTML specification.
11.2.1. Comment Element
The Comment element is used to delimit unneeded text and
comments. The Comment element has been introduced in some
HTML applications but should be replaced by the SGML comment
feature in new HTML interpreters (see Section 2.2.5).
11.2.2. Highlighted Phrase Element
<HP>
The Highlighted Phrase element should be ignored if not
implemented. This element has been replaced by more
meaningful elements (see Section 8).
Example of use:
<HP1>first highlighted phrase</HP1>non-
highlighted text<HP2>second highlighted phrase</HP2> etc.
11.2.3. Plain Text Element
<PLAINTEXT>
The Plain Text element is used to terminates the HTML entity
and to indicate that what follows is not SGML which does not
require parsing. Instead, an old HTTP convention specified
that what followed was an ASCII (MIME ``text/plain'') body.
Its presence is an optimization. There is no closing tag.
Example of use:
<PLAINTEXT>
0001 This is line one of a long listing
0002 file from <ANY@HOST.INC.COM> which is sent
11.2.4. Example and Listing Elements
<XMP> ... </XMP> and <LISTING> ... </LISTING>
The Example and Listing elements have been replaced by the
Preformatted Text element (Section 10.2).
These styles allow text of fixed-width characters to be
embedded absolutely as is into the document. The syntax is:
<LISTING> ... </LISTING>
or
<XMP> ... </XMP>
The text between these tags is typically rendered in a
monospaced font so that any formatting done by character
spacing on successive lines will be maintained.
Between the opening and closing tags:
* The text may contain any ISO Latin-1 printable
characters, except for the end-tag opener. The Example
and Listing elements have historically used
specifications which do not conform to SGML.
Specifically, the text may contain ISO Latin printable
characters, including the tag opener, as long it they
does not contain the closing tag in full.
* SGML does not support this form. HTML interpreters
may vary on how they interpret other tags within
Example and Listing elements.
* Line boundaries within the text are rendered as a
move to the beginning of the next line, except for one
immediately following a start-tag or immediately
preceding an end-tag.
* The horizontal tab character must be interpreted as
the smallest positive nonzero number of spaces which
will leave the number of characters so far on the line
as a multiple of 8. Its use is not recommended.
The Listing element is rendered so that at least 132
characters fit on a line. The Example element is rendered to
that at least 80 characters fit on a line but is otherwise
identical to the Listing element.
11.3. Proposed Features
This section describes proposed HTML elements and entities
that are not currently supported under HTML Levels 1, or 2,
but may be supported in the future.
11.3.1. Additional Character Entities
To indicate special characters, HTML uses entity or numeric
representations. Additional character presentations are
proposed:
CHARACTER REPRESENTATION
Non-breaking space
Soft-hyphen
Registered ®
Copyright ©
11.3.2. Defining Instance Element
<DFN> ... </DFN>
The Defining Instance element indicates the defining
instance of a term. The typical rendering is bold or bold
italic. This element is not widely supported.
11.3.3. Strike Element
<STRIKE> ... </STRIKE>
The Strike element is proposed to indicate strikethrough, a
font style in which a horizontal line appears through
characters. This element is not widely supported.
11.3.4. Underline Element
<U> ... </U>
The Underline element is proposed to indicate that the text
should be rendered as underlined. This proposed tag is not
supported by all HTML interpreters.
Example of use:
The text <U>shown here</U> is rendered in the
document as underlined.
12. Acknowledgments
The HTML document type was designed by Tim Berners-Lee at
CERN as part of the 1990 World Wide Web project. In 1992,
Dan Connolly wrote the HTML Document Type Definition (DTD)
and a brief HTML specification.
Since 1993, a wide variety of Internet participants have
contributed to the evolution of HTML, which has included the
addition of in-line images introduced by the NCSA Mosaic
software for WWW. Dave Raggett played an important role in
deriving the FORMS material from the HTML+ specification.
Dan Connolly and Karen Olson Muldrow rewrote the HTML
Specification in 1994. The document was then edited by the
HTML working group as a whole, with updates being made by
Eric Schieler, Mike Knezovich, and Eric W. Sink at Spyglass,
Inc. Finally, Roy Fielding restructured the entire draft
into its current form.
Special thanks to the many people who have contributed to
this specification:
Terry Allen Marc Andreessen
Tim Berners-Lee Paul Burchard
James Clark Daniel W. Connolly
Roy T. Fielding Peter Flynn
Jay Glicksman Paul Grosso
Eduardo Gutentag Bill Hefley
Chung-Jen Ho Mike Knezovich
Tom Magliery Murray Maloney
Larry Masinter Karen Olson Muldrow
Bill Perry Dave Raggett
E. Corprew Reed Yuri Rubinsky
Eric Schieler James L. Seidman
Eric W. Sink Stuart Weibel
Chris Wilson Francois Yergeau
12.1. Authors' Addresses
Tim Berners-Lee
Director, W3 Consortium
MIT Laboratory for Computer Science
545 Technology Square
Cambridge, MA 02139, U.S.A.
Tel: +1 (617) 253 9670
Fax: +1 (617) 258 8682
Email: timbl@w3.org
Daniel W.
Connolly
Research Technical Staff, W3 Consortium
MIT Laboratory for Computer Science
545 Technology Square
Cambridge, MA 02139, U.S.A.
Fax: +1 (617) 258 8682
Email: connolly@w3.org
URI: http://www.w3.org/hypertext/WWW/People/Connolly/
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