Network Working Group T. Berners-Lee Request for Comments: 1866 MIT/W3C
Category: Standards Track D. ConnollyNovember 1995
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
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" Internet Media Type (RFC 1590) and MIME Content Type (RFC 1521) is defined by this specification.
1. Introduction ........................................... 2 1.1 Scope .................................................. 3 1.2 Conformance ............................................ 3 2. Terms .................................................. 6 3. HTML as an Application of SGML .........................10 3.1 SGML Documents .........................................10 3.2 HTML Lexical Syntax ................................... 12 3.3 HTML Public Text Identifiers .......................... 17 3.4 Example HTML Document ................................. 17 4. HTML as an Internet Media Type ........................ 18
4.1 text/html media type .................................. 18 4.2 HTML Document Representation .......................... 19 5. Document Structure .................................... 20 5.1 Document Element: HTML ................................ 21 5.2 Head: HEAD ............................................ 21 5.3 Body: BODY ............................................ 24 5.4 Headings: H1 ... H6 ................................... 24 5.5 Block Structuring Elements ............................ 25 5.6 List Elements ......................................... 28 5.7 Phrase Markup ......................................... 30 5.8 Line Break: BR ........................................ 34 5.9 Horizontal Rule: HR ................................... 34 5.10 Image: IMG ............................................ 34 6. Characters, Words, and Paragraphs ..................... 35 6.1 The HTML Document Character Set ....................... 36 7. Hyperlinks ............................................ 36 7.1 Accessing Resources ................................... 37 7.2 Activation of Hyperlinks .............................. 38 7.3 Simultaneous Presentation of Image Resources .......... 38 7.4 Fragment Identifiers .................................. 38 7.5 Queries and Indexes ................................... 39 7.6 Image Maps ............................................ 39 8. Forms ................................................. 40 8.1 Form Elements ......................................... 40 8.2 Form Submission ....................................... 45 9. HTML Public Text ...................................... 49 9.1 HTML DTD .............................................. 49 9.2 Strict HTML DTD ....................................... 61 9.3 Level 1 HTML DTD ...................................... 62 9.4 Strict Level 1 HTML DTD ............................... 63 9.5 SGML Declaration for HTML ............................. 64 9.6 Sample SGML Open Entity Catalog for HTML .............. 65 9.7 Character Entity Sets ................................. 66 10. Security Considerations ............................... 69 11. References ............................................ 69 12. Acknowledgments ....................................... 71 12.1 Authors' Addresses .................................... 71 13. The HTML Coded Character Set .......................... 72 14. Proposed Entities ..................................... 75
As HTML is an application of SGML, this specification assumes a working knowledge of [SGML].
This document thus defines a HTML 2.0 (to distinguish it from the previous informal specifications). Future (generally upwardly compatible) versions of HTML with new features will be released with higher version numbers.
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'. As such, it defines the semantics of the HTML syntax and how that syntax should be interpreted by user agents.
* It is a conforming SGML document, and it conforms to the HTML DTD (see 9.1, "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 identified in notes like this throughout this specification.
* 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 [ISO-8859-1] and agrees with [ISO-10646]; that is, each code position listed in 13, "The HTML Coded Character Set" is included, and each code position in the document character set is mapped to the same character as [ISO-10646] 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 [ISO-10646] repertoire. The critical distinction is that numeric character references agree with [ISO-10646] regardless of how the document is encoded.
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 selects a more prescriptive document type definition that eliminates those features. It is set to `IGNORE' by default.
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 allows these features. It is set to `INCLUDE' by default.
Documents generated by translation software or editing software should not contain deprecated idioms.
* 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 4.2.1, "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 6.1, "The HTML Document Character Set".
NOTE - To support non-western writing systems, HTML user agents are encouraged to support `ISO-10646-UCS-2' or similar character encoding schemes and as much of the character repertoire of [ISO-10646] 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 behavior of conforming user agents.
* It allows the user to traverse (or at least attempt to traverse, resources permitting) all hyperlinks from <A> elements in an HTML document.
anchor one of two ends of a hyperlink; typically, a phrase marked as an <A> element.
base URI an absolute URI used in combination with a relative URI to determine another absolute URI.
character An atom of information, for example a letter or a digit. Graphic characters have associated glyphs, whereas 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'.
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, usually 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 presentation 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 two anchors, called the head and the tail. The link goes from the tail to the head. The head and tail are also known as destination and source, respectively.
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.
numeric character reference markup that refers to a character by its code position in the document character set.
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 Uniform Resource Identifier is a formatted string that serves as an identifier for a resource, typically on the Internet. URIs are used in HTML to identify the anchors 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. <URL:http://www.w3.org/>
The term "HTML" refers to both the document type defined here and the markup language for representing instances of this document type.
In the SGML specification, the first production of the SGML syntax 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.
An HTML user agent should use the SGML declaration that is given in 9.5, "SGML Declaration for HTML". According to its document character set, `&#42;' refers to an asterisk character, `*'.
The instance above is regarded as the following sequence of terminals:
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' (9.1, "HTML DTD"). The terminals above parse as:
HTML | \-HEAD | | | \-TITLE | | | \-<TITLE> | | | \-"Parsing Example" | | | \-</TITLE> | \-BODY | \-P | \-<P> | \-"Some text. " | \-EM | | | \-<EM> | | | \-"*wow*" | | | \-</EM> | \-</P>
Some of the elements are delimited explicitly by tags, while the boundaries of others are inferred. The <HTML> element contains a <HEAD> element and a <BODY> element. The <HEAD> contains <TITLE>, which is explicitly delimited by start- and end-tags.
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.
The terminating semicolon on entity or numeric character references is only necessary when the character following the reference would otherwise be recognized as part of the name (see 9.4.5 "Reference End" in [SGML]).
abc &lt def => "abc ","<"," def" abc &#60 def => "abc ","<"," def"
An ampersand is only recognized as markup when it is followed by a letter or a `#' and a 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 --------- ---------- ----------- --------------------- & &amp; &#38; Ampersand < &lt; &#60; Less than > &gt; &#62; Greater than
NOTE - There are SGML mechanisms, CDATA and RCDATA declared content, that allow most `<', `>', and `&' characters to be entered without the use of entity references. Because these mechanisms tend to be used and implemented inconsistently, and because they conflict
with techniques for reducing HTML to 7 bit ASCII for transport, they are deprecated in this version of HTML. See 5.5.2.1, "Example and Listing: XMP, LISTING".
<H1>This is a Heading</H1>
Some elements only have a start-tag without an end-tag. For example, to create a line break, 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, 9.1, "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.
In a start-tag, the element name must immediately follow the tag open delimiter `<'.
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&#62;b">' or `<IMG SRC="eq1.jpg" alt="a&gt;b">'.
* A name token (a sequence of letters, digits, periods, or hyphens). Name tokens are not case sensitive.
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 white space character by an entity reference or numeric character reference as follows:
ENTITY NUMERIC CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION --------- ---------- ----------- --------------------- HT &#9; Tab LF &#10; Line Feed CR &#13; Carriage Return SP &#32; Space " &quot; &#34; Quotation mark & &amp; &#38; Ampersand
The `NAMELEN' parameter in the SGML declaration (9.5, "SGML Declaration for HTML") limits the length of an attribute value to 1024 characters.
Attributes such as ISMAP and COMPACT may be written using a minimized syntax (see 7.9.1.2 "Omitted Attribute Name" in [SGML]). The markup:
<UL COMPACT="compact">
can be written using a minimized syntax:
<UL COMPACT>
NOTE - Some historical implementations only understand the minimized syntax.
NOTE - Some historical HTML implementations incorrectly consider any `>' character to be the termination of a comment.
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
This document type declaration refers to the HTML DTD in 9.1, "HTML DTD".
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.
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Level 2//EN">
This document type declaration also refers to the HTML DTD which appears in 9.1, "HTML DTD".
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN">
This document type declaration refers to the level 1 HTML DTD in 9.3, "Level 1 HTML DTD". Form elements must not occur in level 1 documents.
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Strict//EN"> <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0 Strict Level 1//EN">
These two document type declarations refer to the HTML DTD in 9.2, "Strict HTML DTD" and 9.4, "Strict Level 1 HTML DTD". They refer to the more structurally rigid definition of HTML.
HTML user agents may support other document types. 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.
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 &lt;/P&gt; end tag has been omitted. <P> <IMG SRC ="triangle.xbm" alt="Warning: "> Be sure to read these <b>bold instructions</b>. </BODY></HTML>
Media Type name text
Media subtype name html
Required parameters none
Optional parameters level, charset
Encoding considerations any encoding is allowed
Security considerations see 10, "Security Considerations"
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 [HTTP].
other hand, references to undeclared entities should be treated as data characters.
<div class=chapter><h1>foo</h1><p>...</div> => <H1>,"foo",</H1>,<P>,"..."xxx <P ID=z23> yyy => "xxx ",<P>," yyy Let &alpha; &amp; &beta; be finite sets. => "Let &alpha; & &beta; be finite sets."
[MIME] specifies that a body of type `text/*' is a sequence of lines, each terminated by CRLF, that is, octets 13, 10.
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.
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <HEAD> <TITLE>Introduction to HTML</TITLE> </HEAD>
...
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. This differs from
headings (5.4, "Headings: H1 ... H6"), which are typically displayedwithin the body text flow.
The <LINK> element is typically used to indicate authorship, related indexes and glossaries, older or more recent versions, document hierarchy, associated resources such as style sheets, etc.
* 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, indicating 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 more appropriate. Rather than a <META> element with a URI as the value of the CONTENT attribute, use a <LINK> element.
HTTP servers may 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 meta-information is unspecified and not mandatory. The <META> element only provides an extensible mechanism for identifying and embedding document meta-information -- how it may be used is up to the individual server implementation and the HTML user agent.
NAME specifies the name of the name/value pair. If not present, HTTP-EQUIV gives the name.
CONTENT specifies the value of the name/value pair.
<META HTTP-EQUIV="Expires" CONTENT="Tue, 04 Dec 1993 21:29:02 GMT"> <meta http-equiv="Keywords" CONTENT="Fred"> <META HTTP-EQUIV="Reply-to" content="fielding@ics.uci.edu (Roy Fielding)"> <Meta Http-equiv="Keywords" CONTENT="Barney">
then the server may 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.
An HTTP server must not use the <META> element to form an HTTP response header unless the HTTP-EQUIV attribute is present.
An HTTP server may disregard any <META> elements that specify information controlled by the HTTP server, for example `Server',
`Date', and `Last-modified'.
The <NEXTID> element gives a hint for the name to use for a new <A> element when editing an HTML document. It should be distinct from all NAME attribute values on <A> elements. For example:
<NEXTID N=Z27>
<p>Explanation about important stuff...</BODY>
5.4. Headings: H1 ... H6
The six heading elements, <H1> through <H6>, denote section headings. Although the order and occurrence 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.
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.
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.
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.
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 - Constraints on the processing of <PRE> content 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 - Some historical documents contain <P> tags in <PRE> elements. User agents are encouraged to treat this as 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 (code position 9 in the HTML document character set) 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. Documents should not contain tab characters, as they are not supported consistently.
NOTE - In a previous draft of the HTML specification, the syntax of <XMP> and <LISTING> elements allowed closing tags to be treated as data characters, as long as the tag name was not <XMP> or <LISTING>, respectively.
Since CDATA declared content has a number of unfortunate interactions with processing techniques and tends to be used and implemented inconsistently, HTML documents should not contain <XMP> nor <LISTING> elements -- the <PRE> tag is more expressive and more consistently supported.
The <LISTING> element should be rendered so that at least 132 characters fit on a line. The <XMP> element should be rendered so that at least 80 characters fit on a line but is otherwise identical to the <LISTING> element.
NOTE - In a previous draft, HTML included a <PLAINTEXT> element that is similar to the <LISTING> element, except that there is no closing tag: all characters after the <PLAINTEXT> start-tag are data.
Typically, the <ADDRESS> element is rendered in an italic typeface and may be indented.
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.
The COMPACT attribute suggests that a compact rendering be used.
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>
numbered list.
The content of a <OL> element is a sequence of <LI> elements. For example:
<OL> <LI>Click the Web button to open 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 content of a <DIR> 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>
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>
The content of a <DL> element is a sequence of <DT> elements and/or <DD> elements, usually in pairs. Multiple <DT> may be paired with a single <DD> element. Documents should not contain multiple consecutive <DD> elements.
If the DT term does not fit in the DT column (typically 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>
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 be rendered the same as plain <B>bold </B><I>italic</I>
NOTE - User agents may support the <DFN> element, not included in this specification, as it has been deployed to some extent. It is used to indicate the defining instance of a term, and it is typically rendered in italic or bold italic.
He just couldn't get enough of <cite>The Grapes of Wrath</cite>.
The expression <code>x += 1</code>
is short for <code>x = x + 1</code>.
A singular subject <em>always</em> takes a singular verb.
The only word containing the letters <samp>mt</samp> is dreamt.
<strong>STOP</strong>, or I'll say "<strong>STOP</strong>" again!
Type <SAMP>html-check <VAR>file</VAR> | more</SAMP> to check <VAR>file</VAR> for markup errors.
Typical renderings for idiomatic elements may 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.
NOTE - User agents may support some typographic elements not included in this specification, as they have been deployed to some extent. The <STRIKE> element indicates horizontal line through the characters, and the <U> element indicates an underline.
HREF gives the URI of the head anchor of a hyperlink.
NAME gives the name of the anchor, and makes it available as a head of a hyperlink.
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 include 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. The semantics of link relationships are not specified in this document.
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 head anchor of the hyperlink. The syntax and
semantics of the URN attribute are not yet specified.
METHODS specifies methods to be used in accessing the destination, as a whitespace-separated list of names. The set of applicable names is a function of the scheme of the URI in the HREF attribute. 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.
<P> Pease porridge hot<BR> Pease porridge cold<BR> Pease porridge in the pot<BR> Nine days old.
<HR> <ADDRESS>February 8, 1995, CERN</ADDRESS> </BODY>
HTML user agents may process the value of the ALT attribute as an alternative to processing the image resource indicated by the SRC attribute.
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 an <IMG> element. If the graphic is not essential, then the <IMG> element is appropriate.
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 containing 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 text to use in place of the referenced image resource, for example due to processing constraints or user preference.
ISMAP indicates an image map (see 7.6, "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.
<a href="http://machine/htbin/imagemap/sample"> <IMG SRC="sample.xbm" ISMAP> </a>
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.
NOTE - Use of 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-10646], or some subset that agrees with [ISO-10646]; in particular, all numeric character references must use code positions assigned by [ISO-10646].
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 the HTML document character set only three control characters are allowed: Horizontal Tab, Carriage Return, and Line Feed (code positions 9, 13, and 10).
The HTML DTD references the Added Latin 1 entity set, to allow mnemonic representation of selected Latin 1 characters using only the widely supported ASCII character repertoire. For example:
A hyperlink is a relationship between two anchors, called the head and the tail of the hyperlink[DEXTER]. Anchors are identified by an anchor address: an absolute Uniform Resource Identifier (URI), optionally followed by a '#' and a sequence of characters called a fragment identifier. For example:
http://www.w3.org/hypertext/WWW/TheProject.html http://www.w3.org/hypertext/WWW/TheProject.html#z31
In an anchor address, the URI refers to a resource; it may be used in a variety of information retrieval protocols to obtain an entity that represents the resource, such as an HTML document. The fragment identifier, if present, refers to some view on, or portion of the resource.
Each of the following markup constructs indicates the tail anchor of a hyperlink or set of hyperlinks:
* <A> elements with HREF present.
* <LINK> elements.
* <IMG> elements.
* <INPUT> elements with the SRC attribute present.
* <ISINDEX> elements.
* <FORM> elements with `METHOD=GET'.
These markup constructs refer to head anchors by a URI, either absolute or relative, or a fragment identifier, or both.
In the case of a relative URI, the absolute URI in the address of the head anchor is the result of combining the relative URI with a base absolute URI as in [RELURL]. The base document is taken from the document's <BASE> element, if present; else, it is determined as in [RELURL].
For example, if the base URI is `http://host/x/y.html' and the document contains:
<img src="../icons/abc.gif">
then the user agent uses the URI `http://host/icons/abc.gif' to access the resource, as in [URL]..
To activate a link, the user agent obtains a representation of the resource identified in the address of the head anchor. If the representation is another HTML document, navigation may begin again with this new document.
<LINK> hyperlinks may also be processed without explicit user request; for example, style sheet resources may be processed before or during the processing of the document.
The meaning of fragment identifiers depends on the media type of the representation of the anchor's resource. For `text/html' representations, it refers to the <A> element with a NAME attribute whose value is the same as the fragment identifier. The matching is case sensitive. The document should have exactly one such element. The user agent should indicate the anchor element, for example by scrolling to and/or highlighting the phrase.
For example, if the base URI is `http://host/x/y.html' and the user activated the link denoted by the following markup:
<p> See: <a href="app1.html#bananas">appendix 1</a> for more detail on bananas.
Then the user agent accesses the resource identified by `http://host/x/app1.html'. Assuming the resource is represented using the `text/html' media type, the user agent must locate the <A> element whose NAME attribute is `bananas' and begin navigation there.
<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 8.2.2, "Query Forms: METHOD=GET" for details.
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <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, the chosen hyperlink is the one with the URI `http://host/cgi-bin/imagemap?0,0'.
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.
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 URI of a form defaults to the base URI of the document (see 7, "Hyperlinks").
METHOD selects a method of accessing the action URI. The set of applicable methods is a function of the scheme of the action URI of the form. See 8.2.2, "Query Forms: METHOD=GET" and 8.2.3, "Forms with Side-Effects: METHOD=POST".
ENCTYPE specifies the media type used to encode the name/value pairs for transport, in case the protocol does not itself impose a format. See 8.2.1, "The form-urlencoded Media Type".
The <INPUT> element has a number of attributes. The set of applicable attributes depends on the value of the TYPE attribute.
SIZE specifies the amount of display space allocated to this input field according to its type. The default depends on the user agent.
VALUE The initial value of the field.
NAME symbolic name for the form field corresponding to this element or group of elements.
VALUE The portion of the value of the field contributed by this element.
CHECKED indicates that the initial state is on. At all times, exactly one of the radio buttons in a set is checked. If none of the <INPUT> elements of a set of radio buttons specifies `CHECKED', then the user agent must check the first radio button of the set initially.
The NAME attribute is required as for other input fields. The SRC attribute is required and the ALIGN is optional as for the <IMG> element (see 5.10, "Image: IMG").
NAME indicates that 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.
VALUE indicates a label for the input (button).
You may submit this request internally: <input type=submit name=recipient value=internal><br> or to the external world: <input type=submit name=recipient value=world>
When you are finished, you may submit this request: <input type=submit><br> You may clear the form and start over at any time: <input type=reset>
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.
The initial state has the first option selected, unless a SELECTED attribute is present on any of the <OPTION> elements.
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.
COLS the number of visible columns to display for the text area, in characters.
NAME Specifies the name of the form field.
ROWS The number of visible rows to display for the text area, in characters.
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.
1. The form field names and values are escaped: space characters 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 text field values, are represented as CR LF pairs, i.e. `%0D%0A'.
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&#38;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.
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 7.2, "Activation of Hyperlinks").
NOTE - The URL encoding may result in very 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.
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-formurlencoded' 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.
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> <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>
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"
city "miami"
other "abc\ndefk"
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 line break):
name=John+Doe&gender=male&family=5&city=kent&city=miami& other=abc%0D%0Adef&nickname=J%26D
This is the Document Type Definition for the HyperText Markup Language, level 2.
<!-- html.dtd
Document Type Definition for the HyperText Markup Language (HTML DTD)
$Id: html.dtd,v 1.30 1995/09/21 23:30:19 connolly Exp $
Author: Daniel W. Connolly <connolly@w3.org>See Also: html.decl, html-1.dtd http://www.w3.org/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 and 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 -->
<!--========= 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 "&#38;" -- ampersand -->
<!ENTITY gt CDATA "&#62;" -- greater than --> <!ENTITY lt CDATA "&#60;" -- less than --> <!ENTITY quot CDATA "&#34;" -- 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 emphasis --> <!-- <CODE> Source code phrase --> <!-- <SAMP> Sample text or characters --> <!-- <KBD> Keyboard phrase, e.g. user input --> <!-- <VAR> Variable phrase or substitutable --> <!-- <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 ======================-->
<!ENTITY % linkType "NAMES">
<!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 CDATA #IMPLIED NAME CDATA #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 CDATA #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 CDATA #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 CDATA #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 ""> ]]> <!ENTITY % head.extra "& NEXTID?">
<!ENTITY % head.content "TITLE & ISINDEX? & BASE? %head.extra">
<!ELEMENT HEAD O O (%head.content) +(META|LINK)>
<!-- <HEAD> Document head -->
<!ELEMENT TITLE - - (#PCDATA)* -(META|LINK)> <!ATTLIST TITLE %SDAFORM; "Ti" >
<!-- <TITLE> Title of document -->
<!ELEMENT LINK - O EMPTY> <!ATTLIST LINK HREF CDATA #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 CDATA #REQUIRED >
<!-- <BASE> Base context document -->
<!-- <BASE HREF="..."> Address for this document -->
<!ELEMENT NEXTID - O EMPTY> <!ATTLIST NEXTID N CDATA #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 Meta-information -->
<!-- <META HTTP-EQUIV=...> HTTP response header name --> <!-- <META NAME=...> Meta-information 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 -->
<!-- html-s.dtd
Document Type Definition for the HyperText Markup Language with strict validation (HTML Strict DTD).
$Id: html-s.dtd,v 1.3 1995/06/02 18:55:46 connolly Exp $
Author: Daniel W. Connolly <connolly@w3.org>See Also: http://www.w3.org/hypertext/WWW/MarkUp/MarkUp.html -->
<!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0 Strict//EN"
-- Typical usage:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict//EN"> <html>
...</html> -- >
<!-- Feature Test Entities --> <!ENTITY % HTML.Recommended "INCLUDE">
<!ENTITY % html PUBLIC "-//IETF//DTD HTML 2.0//EN"> %html;
<!-- html-1.dtd
Document Type Definition for the HyperText Markup Language with Level 1 Extensions (HTML Level 1 DTD).
$Id: html-1.dtd,v 1.2 1995/03/29 18:53:10 connolly Exp $
Author: Daniel W. Connolly <connolly@w3.org>See Also: http://info.cern.ch/hypertext/WWW/MarkUp/MarkUp.html
-->
<!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0 Level 1//EN"
-- Typical usage:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Level 1//EN"> <html>
...</html>
-- >
<!-- Feature Test Entities --> <!ENTITY % HTML.Forms "IGNORE">
<!ENTITY % html PUBLIC "-//IETF//DTD HTML 2.0//EN"> %html;
<!-- html-1s.dtd
Document Type Definition for the HyperText Markup Language Struct Level 1
$Id: html-1s.dtd,v 1.3 1995/06/02 18:55:43 connolly Exp $
Author: Daniel W. Connolly <connolly@w3.org>See Also: http://www.w3.org/hypertext/WWW/MarkUp/MarkUp.html -->
<!ENTITY % HTML.Version "-//IETF//DTD HTML 2.0 Strict Level 1//EN"
-- Typical usage:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML Strict Level 1//EN"> <html>
...</html> -- >
<!-- Feature Test Entities -->
<!ENTITY % HTML.Recommended "INCLUDE">
<!ENTITY % html-1 PUBLIC "-//IETF//DTD HTML 2.0 Level 1//EN"> %html-1;
<!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 TAGLVL 100 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 1.17 1995/06/08 14:59:32 connolly Exp $
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 identifier. For example, the following are possible catalog entries:
-- catalog: SGML Open style entity catalog for HTML -- -- $Id: catalog,v 1.3 1995/09/21 23:30:23 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 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
-- ISO latin 1 entity set for HTML -- PUBLIC "ISO 8879-1986//ENTITIES Added Latin 1//EN//HTML" ISOlat1\ sgml
the writer.
GLYPH NAME SYNTAX DESCRIPTION < lt &lt; Less than sign > gt &gt; Greater than signn & amp &amp; Ampersand " quot &quot; Double quote sign
<!-- (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 "&#198;" -- capital AE diphthong (ligature) --> <!ENTITY Aacute CDATA "&#193;" -- capital A, acute accent --> <!ENTITY Acirc CDATA "&#194;" -- capital A, circumflex accent --> <!ENTITY Agrave CDATA "&#192;" -- capital A, grave accent --> <!ENTITY Aring CDATA "&#197;" -- capital A, ring --> <!ENTITY Atilde CDATA "&#195;" -- capital A, tilde --> <!ENTITY Auml CDATA "&#196;" -- capital A, dieresis or umlaut mark --> <!ENTITY Ccedil CDATA "&#199;" -- capital C, cedilla --> <!ENTITY ETH CDATA "&#208;" -- capital Eth, Icelandic --> <!ENTITY Eacute CDATA "&#201;" -- capital E, acute accent --> <!ENTITY Ecirc CDATA "&#202;" -- capital E, circumflex accent -->
<!ENTITY Egrave CDATA "&#200;" -- capital E, grave accent --> <!ENTITY Euml CDATA "&#203;" -- capital E, dieresis or umlaut mark --> <!ENTITY Iacute CDATA "&#205;" -- capital I, acute accent --> <!ENTITY Icirc CDATA "&#206;" -- capital I, circumflex accent --> <!ENTITY Igrave CDATA "&#204;" -- capital I, grave accent --> <!ENTITY Iuml CDATA "&#207;" -- capital I, dieresis or umlaut mark --> <!ENTITY Ntilde CDATA "&#209;" -- capital N, tilde --> <!ENTITY Oacute CDATA "&#211;" -- capital O, acute accent --> <!ENTITY Ocirc CDATA "&#212;" -- capital O, circumflex accent --> <!ENTITY Ograve CDATA "&#210;" -- capital O, grave accent --> <!ENTITY Oslash CDATA "&#216;" -- capital O, slash --> <!ENTITY Otilde CDATA "&#213;" -- capital O, tilde --> <!ENTITY Ouml CDATA "&#214;" -- capital O, dieresis or umlaut mark --> <!ENTITY THORN CDATA "&#222;" -- capital THORN, Icelandic --> <!ENTITY Uacute CDATA "&#218;" -- capital U, acute accent --> <!ENTITY Ucirc CDATA "&#219;" -- capital U, circumflex accent --> <!ENTITY Ugrave CDATA "&#217;" -- capital U, grave accent --> <!ENTITY Uuml CDATA "&#220;" -- capital U, dieresis or umlaut mark --> <!ENTITY Yacute CDATA "&#221;" -- capital Y, acute accent --> <!ENTITY aacute CDATA "&#225;" -- small a, acute accent --> <!ENTITY acirc CDATA "&#226;" -- small a, circumflex accent --> <!ENTITY aelig CDATA "&#230;" -- small ae diphthong (ligature) --> <!ENTITY agrave CDATA "&#224;" -- small a, grave accent --> <!ENTITY aring CDATA "&#229;" -- small a, ring --> <!ENTITY atilde CDATA "&#227;" -- small a, tilde --> <!ENTITY auml CDATA "&#228;" -- small a, dieresis or umlaut mark --> <!ENTITY ccedil CDATA "&#231;" -- small c, cedilla --> <!ENTITY eacute CDATA "&#233;" -- small e, acute accent --> <!ENTITY ecirc CDATA "&#234;" -- small e, circumflex accent --> <!ENTITY egrave CDATA "&#232;" -- small e, grave accent --> <!ENTITY eth CDATA "&#240;" -- small eth, Icelandic --> <!ENTITY euml CDATA "&#235;" -- small e, dieresis or umlaut mark --> <!ENTITY iacute CDATA "&#237;" -- small i, acute accent --> <!ENTITY icirc CDATA "&#238;" -- small i, circumflex accent --> <!ENTITY igrave CDATA "&#236;" -- small i, grave accent --> <!ENTITY iuml CDATA "&#239;" -- small i, dieresis or umlaut mark --> <!ENTITY ntilde CDATA "&#241;" -- small n, tilde --> <!ENTITY oacute CDATA "&#243;" -- small o, acute accent --> <!ENTITY ocirc CDATA "&#244;" -- small o, circumflex accent --> <!ENTITY ograve CDATA "&#242;" -- small o, grave accent --> <!ENTITY oslash CDATA "&#248;" -- small o, slash --> <!ENTITY otilde CDATA "&#245;" -- small o, tilde --> <!ENTITY ouml CDATA "&#246;" -- small o, dieresis or umlaut mark --> <!ENTITY szlig CDATA "&#223;" -- small sharp s, German (sz ligature)-> <!ENTITY thorn CDATA "&#254;" -- small thorn, Icelandic --> <!ENTITY uacute CDATA "&#250;" -- small u, acute accent --> <!ENTITY ucirc CDATA "&#251;" -- small u, circumflex accent --> <!ENTITY ugrave CDATA "&#249;" -- small u, grave accent -->
<!ENTITY uuml CDATA "&#252;" -- small u, dieresis or umlaut mark --> <!ENTITY yacute CDATA "&#253;" -- small y, acute accent --> <!ENTITY yuml CDATA "&#255;" -- small y, dieresis or umlaut mark -->
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 8.1.2, "Input Field: INPUT") -- should be aware and make their users aware of the lack of confidentiality.
[URL] Berners-Lee, T., Masinter, L., and M. McCahill, "Uniform Resource Locators (URL)", RFC 1738, CERN, Xerox PARC, University of Minnesota, December 1994. <URL:ftp://ds.internic.net/rfc/rfc1738.txt>
[HTTP] Berners-Lee, T., Fielding, R., and H. Frystyk Nielsen, "Hypertext Transfer Protocol - HTTP/1.0", Work in Progress, MIT, UC Irvine, CERN, March 1995.
[MIME] Borenstein, N., 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. <URL:ftp://ds.internic.net/rfc/rfc1521.txt>
[RELURL] Fielding, R., "Relative Uniform Resource Locators", RFC 1808, June 1995 <URL:ftp://ds.internic.net/rfc/rfc1808.txt>
[GOLD90] Goldfarb, C., "The SGML Handbook", Y. Rubinsky, Ed., Oxford University Press, 1990.
[DEXTER] Frank Halasz and Mayer Schwartz, "The Dexter Hypertext Reference Model", Communications of the ACM, pp. 30-39, vol. 37 no. 2, Feb 1994.
[IMEDIA] Postel, J., "Media Type Registration Procedure", RFC 1590, USC/Information Sciences Institute, March 1994. <URL:ftp://ds.internic.net/rfc/rfc1590.txt>
[IANA] Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC 1700, USC/Information Sciecnes Institute, October 1994. <URL:ftp://ds.internic.net/rfc/rfc1700.txt>
[SQ91] SoftQuad. "The SGML Primer", 3rd ed., SoftQuad Inc., 1991. <URL:http://www.sq.com/>
[ISO-646] ISO/IEC 646:1991 Information technology -- ISO 7-bit coded character set for information interchange <URL:http://www.iso.ch/cate/d4777.html>
[ISO-10646] ISO/IEC 10646-1:1993 Information technology -- Universal Multiple-Octet Coded Character Set (UCS) -- Part 1: Architecture and Basic Multilingual Plane <URL:http://www.iso.ch/cate/d18741.html>
[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. <URL:http://www.iso.ch/cate/d16338.html>
[SGML] ISO 8879. Information Processing -- Text and Office Systems - Standard Generalized Markup Language (SGML), 1986. <URL:http://www.iso.ch/cate/d16387.html>
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 active participants in the HTML working group, too numerous to list individually, without whom there would be no standards process and no standard. That this document approaches its objective of carefully converging a description of current practice and formalization of HTML's relationship to SGML is a tribute to their effort.
Phone: +1 (617) 253 9670 Fax: +1 (617) 258 8682 EMail: timbl@w3.orgDaniel W. Connolly Research Technical Staff, W3 Consortium MIT Laboratory for Computer Science 545 Technology Square Cambridge, MA 02139, U.S.A.
Phone: +1 (617) 258 8682 EMail: connolly@w3.org URI: http://www.w3.org/hypertext/WWW/People/Connolly/
REFERENCE DESCRIPTION -------------- ----------- &#00; - &#08; Unused &#09; Horizontal tab &#10; Line feed &#11; - &#12; Unused &#13; Carriage Return &#14; - &#31; Unused &#32; Space &#33; Exclamation mark &#34; Quotation mark &#35; Number sign &#36; Dollar sign &#37; Percent sign &#38; Ampersand &#39; Apostrophe &#40; Left parenthesis &#41; Right parenthesis &#42; Asterisk &#43; Plus sign &#44; Comma &#45; Hyphen &#46; Period (fullstop) &#47; Solidus (slash) &#48; - &#57; Digits 0-9 &#58; Colon &#59; Semi-colon &#60; Less than &#61; Equals sign &#62; Greater than &#63; Question mark &#64; Commercial at &#65; - &#90; Letters A-Z &#91; Left square bracket &#92; Reverse solidus (backslash) &#93; Right square bracket &#94; Caret &#95; Horizontal bar (underscore) &#96; Acute accent &#97; - &#122; Letters a-z &#123; Left curly brace &#124; Vertical bar
&#125; Right curly brace &#126; Tilde &#127; - &#159; Unused &#160; Non-breaking Space &#161; Inverted exclamation &#162; Cent sign &#163; Pound sterling &#164; General currency sign &#165; Yen sign &#166; Broken vertical bar &#167; Section sign &#168; Umlaut (dieresis) &#169; Copyright &#170; Feminine ordinal &#171; Left angle quote, guillemotleft &#172; Not sign &#173; Soft hyphen &#174; Registered trademark &#175; Macron accent &#176; Degree sign &#177; Plus or minus &#178; Superscript two &#179; Superscript three &#180; Acute accent &#181; Micro sign &#182; Paragraph sign &#183; Middle dot &#184; Cedilla &#185; Superscript one &#186; Masculine ordinal &#187; Right angle quote, guillemotright &#188; Fraction one-fourth &#189; Fraction one-half &#190; Fraction three-fourths &#191; Inverted question mark &#192; Capital A, grave accent &#193; Capital A, acute accent &#194; Capital A, circumflex accent &#195; Capital A, tilde &#196; Capital A, dieresis or umlaut mark &#197; Capital A, ring &#198; Capital AE dipthong (ligature) &#199; Capital C, cedilla &#200; Capital E, grave accent &#201; Capital E, acute accent &#202; Capital E, circumflex accent &#203; Capital E, dieresis or umlaut mark &#204; Capital I, grave accent
&#205; Capital I, acute accent &#206; Capital I, circumflex accent &#207; Capital I, dieresis or umlaut mark &#208; Capital Eth, Icelandic &#209; Capital N, tilde &#210; Capital O, grave accent &#211; Capital O, acute accent &#212; Capital O, circumflex accent &#213; Capital O, tilde &#214; Capital O, dieresis or umlaut mark &#215; Multiply sign &#216; Capital O, slash &#217; Capital U, grave accent &#218; Capital U, acute accent &#219; Capital U, circumflex accent &#220; Capital U, dieresis or umlaut mark &#221; Capital Y, acute accent &#222; Capital THORN, Icelandic &#223; Small sharp s, German (sz ligature) &#224; Small a, grave accent &#225; Small a, acute accent &#226; Small a, circumflex accent &#227; Small a, tilde &#228; Small a, dieresis or umlaut mark &#229; Small a, ring &#230; Small ae dipthong (ligature) &#231; Small c, cedilla &#232; Small e, grave accent &#233; Small e, acute accent &#234; Small e, circumflex accent &#235; Small e, dieresis or umlaut mark &#236; Small i, grave accent &#237; Small i, acute accent &#238; Small i, circumflex accent &#239; Small i, dieresis or umlaut mark &#240; Small eth, Icelandic &#241; Small n, tilde &#242; Small o, grave accent &#243; Small o, acute accent &#244; Small o, circumflex accent &#245; Small o, tilde &#246; Small o, dieresis or umlaut mark &#247; Division sign &#248; Small o, slash &#249; Small u, grave accent &#250; Small u, acute accent &#251; Small u, circumflex accent &#252; Small u, dieresis or umlaut mark
&#253; Small y, acute accent &#254; Small thorn, Icelandic &#255; Small y, dieresis or umlaut mark
<!ENTITY nbsp CDATA "&#160;" -- no-break space --> <!ENTITY iexcl CDATA "&#161;" -- inverted exclamation mark --> <!ENTITY cent CDATA "&#162;" -- cent sign --> <!ENTITY pound CDATA "&#163;" -- pound sterling sign --> <!ENTITY curren CDATA "&#164;" -- general currency sign --> <!ENTITY yen CDATA "&#165;" -- yen sign --> <!ENTITY brvbar CDATA "&#166;" -- broken (vertical) bar --> <!ENTITY sect CDATA "&#167;" -- section sign --> <!ENTITY uml CDATA "&#168;" -- umlaut (dieresis) --> <!ENTITY copy CDATA "&#169;" -- copyright sign --> <!ENTITY ordf CDATA "&#170;" -- ordinal indicator, feminine --> <!ENTITY laquo CDATA "&#171;" -- angle quotation mark, left --> <!ENTITY not CDATA "&#172;" -- not sign --> <!ENTITY shy CDATA "&#173;" -- soft hyphen --> <!ENTITY reg CDATA "&#174;" -- registered sign --> <!ENTITY macr CDATA "&#175;" -- macron --> <!ENTITY deg CDATA "&#176;" -- degree sign --> <!ENTITY plusmn CDATA "&#177;" -- plus-or-minus sign --> <!ENTITY sup2 CDATA "&#178;" -- superscript two --> <!ENTITY sup3 CDATA "&#179;" -- superscript three --> <!ENTITY acute CDATA "&#180;" -- acute accent --> <!ENTITY micro CDATA "&#181;" -- micro sign --> <!ENTITY para CDATA "&#182;" -- pilcrow (paragraph sign) --> <!ENTITY middot CDATA "&#183;" -- middle dot --> <!ENTITY cedil CDATA "&#184;" -- cedilla --> <!ENTITY sup1 CDATA "&#185;" -- superscript one --> <!ENTITY ordm CDATA "&#186;" -- ordinal indicator, masculine --> <!ENTITY raquo CDATA "&#187;" -- angle quotation mark, right --> <!ENTITY frac14 CDATA "&#188;" -- fraction one-quarter --> <!ENTITY frac12 CDATA "&#189;" -- fraction one-half --> <!ENTITY frac34 CDATA "&#190;" -- fraction three-quarters --> <!ENTITY iquest CDATA "&#191;" -- inverted question mark --> <!ENTITY Agrave CDATA "&#192;" -- capital A, grave accent --> <!ENTITY Aacute CDATA "&#193;" -- capital A, acute accent --> <!ENTITY Acirc CDATA "&#194;" -- capital A, circumflex accent -->
<!ENTITY Atilde CDATA "&#195;" -- capital A, tilde --> <!ENTITY Auml CDATA "&#196;" -- capital A, dieresis or umlaut mark --> <!ENTITY Aring CDATA "&#197;" -- capital A, ring --> <!ENTITY AElig CDATA "&#198;" -- capital AE diphthong (ligature) --> <!ENTITY Ccedil CDATA "&#199;" -- capital C, cedilla --> <!ENTITY Egrave CDATA "&#200;" -- capital E, grave accent --> <!ENTITY Eacute CDATA "&#201;" -- capital E, acute accent --> <!ENTITY Ecirc CDATA "&#202;" -- capital E, circumflex accent --> <!ENTITY Euml CDATA "&#203;" -- capital E, dieresis or umlaut mark --> <!ENTITY Igrave CDATA "&#204;" -- capital I, grave accent --> <!ENTITY Iacute CDATA "&#205;" -- capital I, acute accent --> <!ENTITY Icirc CDATA "&#206;" -- capital I, circumflex accent --> <!ENTITY Iuml CDATA "&#207;" -- capital I, dieresis or umlaut mark --> <!ENTITY ETH CDATA "&#208;" -- capital Eth, Icelandic --> <!ENTITY Ntilde CDATA "&#209;" -- capital N, tilde --> <!ENTITY Ograve CDATA "&#210;" -- capital O, grave accent --> <!ENTITY Oacute CDATA "&#211;" -- capital O, acute accent --> <!ENTITY Ocirc CDATA "&#212;" -- capital O, circumflex accent --> <!ENTITY Otilde CDATA "&#213;" -- capital O, tilde --> <!ENTITY Ouml CDATA "&#214;" -- capital O, dieresis or umlaut mark --> <!ENTITY times CDATA "&#215;" -- multiply sign --> <!ENTITY Oslash CDATA "&#216;" -- capital O, slash --> <!ENTITY Ugrave CDATA "&#217;" -- capital U, grave accent --> <!ENTITY Uacute CDATA "&#218;" -- capital U, acute accent --> <!ENTITY Ucirc CDATA "&#219;" -- capital U, circumflex accent --> <!ENTITY Uuml CDATA "&#220;" -- capital U, dieresis or umlaut mark --> <!ENTITY Yacute CDATA "&#221;" -- capital Y, acute accent --> <!ENTITY THORN CDATA "&#222;" -- capital THORN, Icelandic --> <!ENTITY szlig CDATA "&#223;" -- small sharp s, German (sz ligature) --> <!ENTITY agrave CDATA "&#224;" -- small a, grave accent --> <!ENTITY aacute CDATA "&#225;" -- small a, acute accent --> <!ENTITY acirc CDATA "&#226;" -- small a, circumflex accent --> <!ENTITY atilde CDATA "&#227;" -- small a, tilde --> <!ENTITY auml CDATA "&#228;" -- small a, dieresis or umlaut mark --> <!ENTITY aring CDATA "&#229;" -- small a, ring --> <!ENTITY aelig CDATA "&#230;" -- small ae diphthong (ligature) --> <!ENTITY ccedil CDATA "&#231;" -- small c, cedilla --> <!ENTITY egrave CDATA "&#232;" -- small e, grave accent --> <!ENTITY eacute CDATA "&#233;" -- small e, acute accent --> <!ENTITY ecirc CDATA "&#234;" -- small e, circumflex accent --> <!ENTITY euml CDATA "&#235;" -- small e, dieresis or umlaut mark --> <!ENTITY igrave CDATA "&#236;" -- small i, grave accent --> <!ENTITY iacute CDATA "&#237;" -- small i, acute accent --> <!ENTITY icirc CDATA "&#238;" -- small i, circumflex accent --> <!ENTITY iuml CDATA "&#239;" -- small i, dieresis or umlaut mark --> <!ENTITY eth CDATA "&#240;" -- small eth, Icelandic --> <!ENTITY ntilde CDATA "&#241;" -- small n, tilde --> <!ENTITY ograve CDATA "&#242;" -- small o, grave accent -->
<!ENTITY oacute CDATA "&#243;" -- small o, acute accent --> <!ENTITY ocirc CDATA "&#244;" -- small o, circumflex accent --> <!ENTITY otilde CDATA "&#245;" -- small o, tilde --> <!ENTITY ouml CDATA "&#246;" -- small o, dieresis or umlaut mark --> <!ENTITY divide CDATA "&#247;" -- divide sign --> <!ENTITY oslash CDATA "&#248;" -- small o, slash --> <!ENTITY ugrave CDATA "&#249;" -- small u, grave accent --> <!ENTITY uacute CDATA "&#250;" -- small u, acute accent --> <!ENTITY ucirc CDATA "&#251;" -- small u, circumflex accent --> <!ENTITY uuml CDATA "&#252;" -- small u, dieresis or umlaut mark --> <!ENTITY yacute CDATA "&#253;" -- small y, acute accent --> <!ENTITY thorn CDATA "&#254;" -- small thorn, Icelandic --> <!ENTITY yuml CDATA "&#255;" -- small y, dieresis or umlaut mark -->