HTML Reference Manual
Last Modified: 8 September 1995
Index
Introduction
Conformance
Sandia Requirements
General Syntax
Comments
A,
ABBREV,
ACRONYM,
ADDRESS,
AU,
B,
BANNER,
BASE,
BASEFONT,
BIG,
BLINK,
BLOCKQUOTE,
BODY,
BQ,
BR,
CAPTION,
CENTER,
CITE,
CODE,
CREDIT,
DD,
DEL,
DFN,
DIR,
DIV,
DL,
DT,
EM,
FN,
FIG,
FONT,
FORM,
H1,
H2,
H3,
H4,
H5,
H6,
HEAD,
HP,
HR,
HTML,
I,
IMG,
INPUT,
INS,
ISINDEX,
KBD,
LANG,
LH,
LI,
LINK,
LISTING,
MENU,
META,
NEXTID,
NOBR,
NOTE,
OL,
OPTION,
OVERLAY,
P,
PERSON,
PLAINTEXT,
PRE,
Q,
S,
SAMP,
SELECT,
SMALL,
STRIKE,
STRONG,
SUB,
SUP,
TAB,
TABLE,
TD,
TEXTAREA,
TH,
TITLE,
TR,
TT,
U,
UL,
VAR,
WBR,
XMP
Uniform Resource Locator (URL)
Special Characters
Standard Icons
Disclaimer
Acknowledgements
HTML is an evolving language which
is used to construct documents which
can be viewed by World Wide Web browsers.
HTML is attempting to be standardized by the
WWW consortium
but that standard is also evolving.
HTML is currently defined at Version 2, but the final version
of the RFC has not yet been officially published.
This Reference Manual will be updated to the official RFC
whenever that is published.
The Version 2 Specification also declared some earlier elements obsolete.
There is active work on-going to finalize the specifications of
a Version 3 of HTML which contains significant new features.
HTML+ was a draft of the proposals for Version 3.
In addition, there is some talk of an interim Version 2.1 to
standardize a few of the more desired Version 3 features earlier
than the expected final agreement on a Version 3.
This document attempts to include most of the extensions
in the current proposal for Version 3, since some Version 3 features are
beginning to be implemented in some browsers at use at Sandia.
(ed:Most "Elements Allowed Within..." and
"Allowed In Content Of..." still need updating,
as does the meanings of some new Version 3 attributes.)
While this may introduce confusion by describing non-existent features,
there is value in being aware of the proposed directions in this language.
The inclusion of Version 3 proposals intentionally excludes
the additions to handle Mathematical Expressions
since this area is still in progress.
For further information about Version 3, see
Acknowledgements.
Not all browsers implement all features of Version 2.
In addition, some browsers define and handle their own extensions.
A browser is supposed to ignore any element or attribute
of the language that it is not designed to handle.
As of the IETF HTML BOF of 26 July 1994,
the Version 2 Standard Specification defined
five levels of conformance of the HTML Language elements.
Browsers can choose (and declare) what level of
conformance they fulfill.
- Level 0
- Mandatory. Heading, lists, anchors, etc.
(A text only browser is expected to have Level 0 conformance.)
- Level 1
- Images, Emphasis
- Level 2
- Forms, Character Definitions
- Level 3
- Tables, Figures, etc.
(proposed in Version 3)
- Level 4
- Mathematical formulae
(proposed in Version 3, not existing practice,
not yet included in this reference)
The Integrated Information Services Division of Sandia National Laboratories
has established a set of requirements for HTML documents prepared at
Sandia National Laboratores.
These requirements are an attempt to maintain document consistency,
provide some configuration management hooks,
automatically insert links between documents and
identify document ownership within Sandia's Internal Web.
For individuals with access to Sandia's Internal Web, a more complete
specification
of those requirements is available.
In addition to requirements, that specification also references documents
with style guide suggestions for Sandia HTML authors.
While this Reference Manual attempts to identify the Sandia requirements,
for any conflicts, the specification page on the Internal Web takes precedence.
In addition to the SGML identification line described in
General Syntax,
and the HTML elements and attributes which are required (see
ADDRESS,
BODY,
HEAD,
HTML,
IMG,
META,
LINK,
TITLE),
all documents shall have a "point-of-contact" name
identified in the document as part of the ADDRESS
element that is e-mail enabled by surrounding the name with the
<A> element.
Sandia authors should use Sandia's cgi-bin e-mail program
to generate a mail message submission form
by setting the HREF attribute of the A element to one of the addresses
identified in the Sandia
specification
document.
Until all the browsers which the CIO organization of Sandia suppports,
and for which Sandia has a site license, accept the newly emerging
mailto: URL access code,
Sandia authors of documents on our Internal web are discouraged
from setting the HREF attribute of the A element to
"mailto:ename@sandia.gov"
This mechanism is acceptable for documents on the external web,
but authors should also display the e-mail address of the
"point-of-contact" name so that manually initiated e-mail
is possible.
All Sandia documents shall also display a line indicating the
date the document was last modified. This is usually placed with
the ADDRESS element at either the beginning or end of the document.
Recommended format is: Last Modified: 18 Apr 1995
Any Sandia document which is part of
a set of HTML subdocuments which form a sequence or hierarchy should
include two specific LINK elements
identifying the REL values of next and previous.
In addition, the author should also place icons or text enabled with
the <A> element
at the beginning and/or end of the BODY section to
make it easy to jump to the document next or previous in the sequence.
Only one next and one previous relationship
may be specified in a document.
HTML is an application of
ISO Standard 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.
HTML is one such markup language. Its syntax follows the syntax of SGML.
An HTML file is an ASCII file of text which also includes instructions
to a browser, mostly about displaying the text.
To formally identify the file as containing HTML elements,
the beginning of the file should contain a line in SGML syntax
identifying the version of HTML being used.
For HTML Version 2.0, this line is
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
- Sandia Requirements
-
The SGML specification line identifying the file as HTML is required before the
<HTML> element in the file.
It should either specify the version number of HTML to which the file conforms
by using a line like the one above,
or simply specify that the file is HTML by using the line:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
Unless explicitly instructed otherwise, the browser normally
treats all white space that is not a blank
(e.g. tabs, end-of-line characters, etc.) as a single blank,
and collapses multiple white space to a single blank.
The browser instructions consist of HTML elements
which are HTML element names, optionally followed by HTML attributes,
all surrounded by "<" and ">"
Attributes may be followed by an equals sign and some
"value".
White space is allowed around the equals sign.
The standard requires that the "value"
must be surrounded by single or double quotes,
but many browsers do not enforce this syntax.
The maximum length of "value" (after parsing) is
defined as 1024 characters.
Most HTML elements are designed to surround some content, usually text,
and thus have both a beginning and ending tag.
The ending tag is simply the element name preceded by a "/"
all surrounded by "<" and ">"
HTML names must begin with a letter and are followed by
up to 33 letters, digits, periods, or hyphens.
The standard defines the HTML names in upper case,
but (except for Special Characters)
browsers are supposed to ignore the case of HTML names.
- Description
- To include comments in an HTML document
that will be ignored by the HTML browser, surround
them with
<!-- and -->.
After the beginning comment delimiter,
all text up to the next occurrence of --> is ignored.
Hence comments cannot be nested.
White space is allowed between the closing -- and >,
but not between the opening <! and --.
- Minimum Attributes
<!--characters... -->
- Common Usage
<!--
characters...
characters...
-->
- Variations
- Not all browsers will properly handle HTML elements
(i.e. an "
<") inside of a comment.
Some browsers will treat as comments any element that
begins with "<!"
and not require the two dashes
at the beginning "<!--"
or the end "-->" of the commented text.
This syntax is actually SGML, and the browser is simply ignoring
unrecognized SGML commands.
Such browsers will terminate this "comment" upon the first
occurance of a ">".
Some browsers prohibit the double dash "--"
sequence from appearing anywhere within the commented text
except at the end.
Version 2 specifies the double dash at beginning and end as required.
A few early browsers recognized an element
<comment> </comment>.
The Version 2 specification delcares this element obsolete.
Version 2 is proposing to add the SGML comment syntax to HTML elements.
This proposal would begin a comment with a double dash encountered
inside any HTML element (but not inside quotes),
and treat everything as comments
(including any ">", "<",
or quote character)
until the next occuring double dash. Such syntax would allow HTML
elements within a comment.
- Description
- The A element brackets (or anchors) a piece of text (and/or image) which
is identified as a hypertext link.
The A element must have either an HREF attribute or a NAME attribute.
The HREF attribute identifies a destination URL,
and the bracketed text is rendered as a hypertext link to the URL.
Browsers will display the contents of an A element with an HREF attribute
in a special manner to indicate that if the contents are selected,
the browser will execute that hypertext link.
The NAME attribute identifies a destination tag, and the bracketed text
is thereby identified as an available hypertext target
within this document.
Browsers do not display the contents of an A element with a NAME attribute
in any special way.
However, an A element with an HREF attribute can now be constructed
by using the document URL suffixed with
#name.
This will load the document, but will position the display
starting at the location of this NAME tag.
An A element with an HREF attribute can also be constructed
to jump directly to this destination tag within the same document
by a URL consisting solely of #name
The presence of REL=relation
in document A with HREF to document/object B
identifies a relationship that B has to A that A recognizes/authorizes/verifies.
The presence of REV=relation
of the identical relation
in document B with HREF to document/object A
identifies a desired/expected/claimed relationship that B has to A,
but must be verified by checking with A.
- Minimum Attributes
<A HREF="..." >characters...
</A>
or
<A NAME="..." >characters...
</A>
- All Possible Attributes
<A HREF="..."
NAME="..."
REL="..."
REV="..."
URN="..."
TITLE="..."
METHODS="..."
ID="..."
LANG="..."
CLASS="..."
MD="..."
SHAPE="...">characters...
</A>
- Elements Allowed Within...
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- HTML+ and Version 3 propose changing the NAME attribute to ID
and adding an ID attribute for various elements
including the paragraph and heading elements.
Version 3 specifically identifies NAME as obsolete and replaced by ID.
At present REV and REL are rarely used or supported,
and are Level 1 attributes,
but are of growing interest to automated document environments.
These relationships are more commonly identified in the HEAD
of the document using the LINK element.
REL and REV are a comma-separated set of relationship(s) of the HREF link.
These relationships and their semantics are registered with the
HTML authority.
Examples are
UseIndex, UseGlossary, Annotation, Reply, Embed,
Precedes, Subdocument, Present, Search, Supersedes, History, Made,
Owns, Approves, Supports, Refutes, Includes, Interested.
URN is for a Universal Resource Number, and is not currently
used or supported, and is a Level 1 attribute.
TITLE is little used or supported, and is a Level 1 attribute,
but is expected to be the title of the HREF document.
METHODS is little used or supported, but is expected to be
a comma-separated list of HTTP METHODS supported by the
object and accessible to the user.
LANG, CLASS, and MD are the general attributes proposed by Version 3.
SHAPE is proposed by Version 3 to provide a mechanism to define
multiple A elements and corresponding "hotzones" within the
proposed FIG element, to perform the equivalent function
of ISMAP without the need for writing a responding cgi-bin program.
A is a Level 0 element.
- Description
- The ABBREV element
changes the character rendering of the
contents of the element to logically represent
abbreviations.
- Minimum Attributes
<ABBREV>characters... </ABBREV>
- All Possible Attributes
<ABBREV
ID="..."
LANG="..."
CLASS="...">characters...
</ABBREV>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The ABBREV element is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- The ACRONYM element
changes the character rendering of the
contents of the element to logically represent
acronyms.
- Minimum Attributes
<ACRONYM>characters... </ACRONYM>
- All Possible Attributes
<ACRONYM
ID="..."
LANG="..."
CLASS="...">characters...
</ACRONYM>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The ACRONYM element is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- The AU element
changes the character rendering of the
contents of the element to logically represent
the name of an author.
- Minimum Attributes
<AU>characters... </AU>
- All Possible Attributes
<AU
ID="..."
LANG="..."
CLASS="...">characters...
</AU>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The AU element is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- The ADDRESS element defines a separated multi-line set of text
to be rendered for address information.
- Minimum Attributes
<ADDRESS>characters...
</ADDRESS>
- All Possible Attributes
<ADDRESS
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
NOWRAP>characters...
</ADDRESS>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
<P>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- ADDRESS text is typically rendered in italics.
The ID, LANG, CLASS, CLEAR, and NOWRAP attributes are proposed
in Version 3.
ADDRESS is a Level 0 element.
- Sandia Requirements
- An ADDRESS element is required to identify a "point-of-contact".
For details, see the Sandia Requirements.
- Description
- The B element changes the physical rendering of the
contents of the element to a bold font.
- Minimum Attributes
<B>characters...
</B>
- All Possible Attributes
<B
ID="..."
LANG="..."
CLASS="...">characters...
</B>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- Browsers who do not have bold may render in some other manner.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The BANNER element is proposed for corporate logos, navigation aids,
disclaimers and other information which shouldn't be scrolled
with the rest of the document.
- Minimum Attributes
<BANNER>characters...
</BANNER>
- All Possible Attributes
<BANNER ID="..."
LANG="..."
CLASS="...">characters...
</BANNER>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<BODY>
- Variations
- This is a proposed Version 3 element.
- Description
- The BASE element provides the URL
base to be used for any relative URL links in this document.
It must be a complete file name,
and is usually the original URL of this document.
If this file is moved, having the BASE set to the original URL
eliminates the need to also move all the documents which are
identified by relative URL links in this document.
- Minimum Attributes
<BASE HREF="...">
- All Possible Attributes
<BASE HREF="...">
- Elements Allowed Within...
- Allowed In Content Of...
<HEAD>
- Variations
- This is a Level 0 element.
- Description
- Change the document base font size to one of the seven defined sizes.
The default is 3.
- Minimum Attributes
<BASEFONT SIZE=1|2|3|4|5|6|7>
- All Possible Attributes
<BASEFONT SIZE=1|2|3|4|5|6|7>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The BASEFONT element is a Netscape extension.
- Description
- The BIG element changes the physical rendering of the
contents of the element to a bigger font than normal text, if practical.
- Minimum Attributes
<BIG>characters...
</BIG>
- All Possible Attributes
<BIG
ID="..."
LANG="..."
CLASS="...">characters...
</BIG>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The BIG element is proposed in Version 3.
All character definition elements are Level 2.
- Description
- The BLINK element changes the physical rendering of the
contents of the element to a blinking font.
- Minimum Attributes
<BLINK>characters...
</BLINK>
- All Possible Attributes
<BLINK>characters...
</BLINK>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- This element is not listed in the standard,
and many browsers ignore this element.
Many users find the use of this element annoying.
It should be restricted to short term use for new information.
Netscape 1.1N permits users to disable the rendering of this element.
- Description
- The BLOCKQUOTE element defines a separated multi-line set of text
to be rendered as quoted text.
- Minimum Attributes
<BLOCKQUOTE>
</BLOCKQUOTE>
- All Possible Attributes
<BLOCKQUOTE>
</BLOCKQUOTE>
- Elements Allowed Within...
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<P>
<UL>
<OL>
<DIR>
<MENU>
<DL>
<PRE>
<BLOCKQUOTE>
<FORM>
<ISINDEX>
<HR>
<ADDRESS>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- The contents of the BLOCKQUOTE element is typically rendered
slightly indented both left and right, and/or italic font.
Early browsers displayed the contents with a vertical line
of ">" characters down the left margin
to indicate quotation in the Internet mail style.
Version 3 proposes replacing the BLOCKQUOTE element with the
BQ element.
BLOCKQUOTE is a Level 0 element.
- Description
- The BODY element contains all the content of the document,
as opposed to the
HEAD, which contains information about
the document. All displayable elements should be within the content
of the BODY.
- Minimum Attributes
- All Possible Attributes
<BODY
ID="..."
LANG="..."
CLASS="..."
BACKGROUND="..."
BGCOLOR="#rrggbb"
TEXT="#rrggbb"
LINK="#rrggbb"
VLINK="#rrggbb"
ALINK="#rrggbb">
</BODY>
- Elements Allowed Within...
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<P>
<UL>
<OL>
<DIR>
<MENU>
<DL>
<PRE>
<BLOCKQUOTE>
<FORM>
<ISINDEX>
<HR>
<ADDRESS>
- Allowed In Content Of...
<HTML>
- Variations
- The HTML, HEAD, and BODY elements were introduced with
Version 2, and are currently optional, but are considered
Level 0 elements by the Version 2 standard.
Version 3 proposes the attributes ID, LANG, CLASS, and BACKGROUND.
Netscape 1.1 includes the BACKGROUND attribute, which is a URL to point
to an image to be reproduced to fill the background of the document.
The BGCOLOR, LINK, VLINK, and ALINK attributes are Netscape 1.1 extensions.
- Sandia Requirements
- The HTML, HEAD and BODY elements are required.
- Description
- The BQ element defines a multi-line set of text
to be rendered as quoted text.
The content of the BQ element may optionally contain the
CREDIT element.
- Minimum Attributes
<BQ>
</BQ>
- All Possible Attributes
<BQ
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
NOWRAP>
</BQ>
- Elements Allowed Within...
<CREDIT>
-others TBD-
- Allowed In Content Of...
<BQ>
-others TBD-
- Variations
- The BQ element is proposed in Version 3 as a replacement
for the BLOCKQUOTE element.
Version 3 does not indicate the typical rendering of the contents
of the BQ element, but does indicate that it may not imply
text separation.
- Description
- The BR element breaks for a new line, but does not produce
separation of text.
- Minimum Attributes
<BR>
- All Possible Attributes
<BR
CLEAR=left|right|all|"..."
ID="..."
LANG="..."
CLASS="...">
- Elements Allowed Within...
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- The CLEAR attribute is a Netscape extension and was added
to force the line break to clear possible floating graphic images.
Version 3 includes CLEAR, and proposes the remaining attributes.
The BR element is Level 0.
- Description
- The CAPTION element is used to label a table or figure.
- Minimum Attributes
<CAPTION>characters... </CAPTION>
- All Possible Attributes
<CAPTION
ALIGN=top|bottom|left|right
ID="..."
LANG="..."
CLASS="...">characters... </CAPTION>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<FIG>
<TABLE>
- Variations
- The CAPTION element is proposed in Version 3.
There is some discussion that the only values that make sense
for the ALIGN attribute when CAPTION is used in the contents
of the TABLE element are
top|bottom
This element is an extension in Netscape 1.1.
- Description
- All contents within the CENTER element is to be
centered between the current left and right margin.
- Minimum Attributes
<CENTER>characters... </CENTER>
- All Possible Attributes
<CENTER>characters... </CENTER>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<A>
-TBD-
- Variations
- The CENTER element is a Netscape extension.
It was provided as an alternative to the HTML+ and Version 3
ALIGN="center" proposed new attribute for all the
text block elements such as the
<P> paragraph and
<H?> header elements.
There is still debate as to which mechanism is preferred,
but the current Version 3 specification only includes the ALIGN
attribute, not the CENTER element.
- Description
- The CITE element changes the character rendering of the
contents of the element to logically represent a citation.
- Minimum Attributes
<CITE>characters...
</CITE>
- All Possible Attributes
<CITE
ID="..."
LANG="..."
CLASS="...">characters...
</CITE>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- This is typically rendered in italics.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The CODE element changes the character rendering of the
contents of the element to logically represent computer code.
- Minimum Attributes
<CODE>characters...
</CODE>
- All Possible Attributes
<CODE
ID="..."
LANG="..."
CLASS="...">characters...
</CODE>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- This is usually rendered in a fixed-width font.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The CREDIT element is used to name the source of a
block quotation or figure.
- Minimum Attributes
<CREDIT>characters... </CREDIT>
- All Possible Attributes
<CREDIT
ID="..."
LANG="..."
CLASS="...">characters... </CREDIT>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<BQ>
<FIG>
- Variations
- The CREDIT element is proposed in Version 3.
Version 3 does not indicate the typical rendering for the contents
of the CREDIT element, nor whether that rendering should be different
or separated from the enclosing block quotation or figure.
- Description
- The DD element identifies the separated multi-line
definition item in a DL definition list.
- Minimum Attributes
<DD>characters...
- All Possible Attributes
<DD>characters...
</DD>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
<P>
<UL>
<OL>
<DIR>
<MENU>
<DL>
<PRE>
<BLOCKQUOTE>
<FORM>
<ISINDEX>
- Allowed In Content Of...
<DL>
- Variations
- This is typically rendered as normal text, indented.
Most browsers assume that the contents of the element
ends when it encounters a
<DT> or
another <DD> or the </DL>
element to end the list, and thus do not require the
ending tag.
All list elements are Level 0.
- Description
- The DEL element
changes the character rendering of the
contents of the element to logically represent
deleted text, for instance in modifications in legal documents.
- Minimum Attributes
<DEL>characters... </DEL>
- All Possible Attributes
<DEL
ID="..."
LANG="..."
CLASS="...">characters...
</DEL>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The DEL element is a Version 3 proposed element.
While this will typically be rendered by strikethru characters,
the DEL element is preferred over using the S or STRIKE elements.
All character definition elements are Level 2.
- Description
- The DFN element changes the character rendering of the
contents of the element to logically represent a
defining instance of a term.
- Minimum Attributes
<DFN>characters... </DFN>
- All Possible Attributes
<DFN
ID="..."
LANG="..."
CLASS="...">characters...
</DFN>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The DFN element is not widely implemented, but
is usually rendered bold or bold italic.
The ID, LANG, and CLASS attributes are proposed in Version 3.
It is a Version 2 and Version 3 proposed element.
- Description
- The DIR element defines an unordered list consisting of a number of
single-line
<LI> elements, usually less than 20
characters in length. These may be arranged in columns across the page.
- Minimum Attributes
<DIR></DIR>
- All Possible Attributes
<DIR COMPACT>
</DIR>
- Elements Allowed Within...
<LI>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- This list type is not commonly implemented, and
is often rendered identically to UL.
Specifying
<UL PLAIN WRAP=HORIZ> is proposed
in Version 3 as a replacement for the DIR element.
All list elements are Level 0.
- Description
- The DIV element is proposed to be used
with the CLASS attribute to represent different kinds of containers,
e.g. chapter, section, abstract, or appendix.
- Minimum Attributes
<DIV>characters...
</DIV>
- All Possible Attributes
<DIV
ID="..."
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
NOWRAP
CLEAR=left|right|all|"...">characters...
</DIV>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<BODY>
- Variations
- This is a proposed Version 3 element.
<DIV ALIGN=center> is the proposed replacement
for the non-standard CENTER element.
- Description
- The DL element defines a definition list. Each item in the
list is expected to have two parts, identified by the
<DT> and <DD> elements.
- Minimum Attributes
<DL></DL>
- All Possible Attributes
<DL
COMPACT
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"...">
</DL>
- Elements Allowed Within...
<LH>
<DT>
<DD>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- The COMPACT attribute suggests rendering the list in
a physically compact way, but is not implemented by many browsers.
Version 3 proposes the general ID, LANG, CLASS, and CLEAR attributes.
To obtain a specific look, it has been the practice to construct
a DL with DD elements but empty or missing DT elements.
Version 3 proposes a new NOTE element as the
preferred alternative to achieve the effect desired.
All list elements are Level 0.
- Description
- The DT element identifies the separated term item in a DL definition list.
- Minimum Attributes
<DT>characters...
- All Possible Attributes
<DT>characters...
</DT>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<DL>
- Variations
- This is typically rendered in a bold font, but not indented.
Most browsers assume that the contents of the element
ends when it encounters a
<DD> or
another <DT> or the </DL>
element to end the list, and thus do not require the
ending tag.
All list elements are Level 0.
- Description
- The EM element changes the character rendering of the
contents of the element to logically emphasize the text.
- Minimum Attributes
<EM>characters...
</EM>
- All Possible Attributes
<EM
ID="..."
LANG="..."
CLASS="...">characters...
</EM>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- Usually rendered in italics.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The FIG element is an advanced form of the
IMG element to define an image, with optional
overlays, text elements and "hotzones", to be inserted
within a document.
The structure of the contents of the FIG element expects
a series of optional overlay images defined by OVERLAY elements,
followed by an optional CAPTION element,
followed by text to be presented as an alternative to the image(s)
and which may contain normal text elements as well as
hypertext links defined by A elements with
SHAPE attributes to identify "hotzones" on the image,
finally completed by an optional CREDIT element.
- Minimum Attributes
<FIG SRC="..."></FIG>
- All Possible Attributes
<FIG SRC="..."
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
NOFLOW
MD="..."
ALIGN=left|right|center|justify|bleedleft|bleedright
WIDTH=value
HEIGHT=value
UNITS="..."
IMAGEMAP="..."></FIG>
- Elements Allowed Within...
<OVERLAY>
<CAPTION>
<CREDIT>
-TBD- (ed: all normal markup elements?)
- Allowed In Content Of...
-TBD-
- Variations
- The FIG element is proposed in Version 3 as a sophisticated
alternative to the IMG element, especially to enhance the capabilities
of the ALT text for non-graphical presentations of HTML documents,
as well as a way to accomplish the common use of the ISMAP attribute
of the IMG element without the need for a responding cgi-bin program.
- Description
- The FN element logically identifies text to be presented
as a footnote. The reference location for the footnote is expected
to be an A element whose HREF attribute references the ID of the
FN element.
- Minimum Attributes
<FN ID="...">characters... </FN>
- All Possible Attributes
<FN ID="..."
LANG="..."
CLASS="...">characters... </FN>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The FN element is a Version 3 proposed element.
Version 3 specifies that when practical, the browser should
render the FN element as pop-up notes.
Version 3 does not specify an expected rendering when the footnote
text is simply displayed where it occurs in the document.
However, Version 3 does state that the FN element does not imply
text separation. Therefore, common practice expects that the
contents of the FN element would begin with a markup element
which produces separation, e.g. the P element.
- Description
- The FONT element changes the font size of the following characters
to one of the seven defined sizes, or plus or minus from the document
BASEFONT
size.
- Minimum Attributes
<FONT SIZE=[+|-]1|2|3|4|5|6|7>
- All Possible Attributes
<FONT SIZE=[+|-]1|2|3|4|5|6|7>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The FONT element is a Netscape extension.
- Description
- The FORM element creates a fill-out form.
The browser permits the user to enter information in the fields of
the form and sends this information to a cgi-bin script on a server
identified as a URL by the ACTION attribute.
METHOD=GET (the default) appends the input information to the
ACTION URL which becomes
the value of the environment variable
QUERY_STRING.
METHOD=POST (the preferred) sends the input information in a data body
which is available on stdin with the data length set
in the environment variable CONTENT_LENGTH.
Form data is a stream of name=value pairs
separated by the & character.
Each name=value pair is URL encoded,
i.e. spaces are changed into the plus character and some characters
are encoded into hexadecimal.
At least one of the following is expected inside the FORM
contents: INPUT, SELECT, TEXTAREA.
- Minimum Attributes
<FORM></FORM>
- All Possible Attributes
<FORM ACTION="..."
METHOD=GET|POST
ENCTYPE="..."
SCRIPT="...">
</FORM>
- Elements Allowed Within...
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<P>
<UL>
<OL>
<DIR>
<MENU>
<DL>
<PRE>
<BLOCKQUOTE>
<ISINDEX>
<HR>
<ADDRESS>
<INPUT>
<SELECT>
<TEXTAREA>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<LI>
- Variations
- Only the default value of
application/x-www-form-urlencoded
is currently defined for the ENCTYPE attribute,
but is expected to allow all registered MIME types.
Version 2 only defines ACTION for the http: access type.
Version 3 proposes the SCRIPT attribute to specify a URL which
contains a limited syntax script to be downloaded to the browser
for execution to preprocess the FORM output before sending it
to the ACTION destination.
All elements concerning FORM are Level 2.
- Description
- The H1 element identifies text to be separated and displayed
as the most prominent header.
- Minimum Attributes
<H1>characters...
</H1>
- All Possible Attributes
<H1 ID="name"
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
CLEAR=left|right|all|"..."
SEQNUM=nnn
SKIP=nnn
DINGBAT=entity-name
SRC="..."
MD="..."
NOWRAP>characters...
</H1>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- The specification recommends that a document use the
header elements in order, without breaks, beginning with H1.
(ed: I have not identified a browser that enforces this.)
The ID attribute is proposed in HTML+ and Version 3
to replace the NAME attribute
in the A element to establish internal hyperlink destinations.
All other attributes are proposed in Version 3.
Typical rendering is bold, very large font, centered;
when printed causes a page break.
Headings are Level 0 elements.
- Description
- The H2 element identifies text to be separated and displayed
less prominently than H1 but more prominently than H3.
- Minimum Attributes
<H2>characters...
</H2>
- All Possible Attributes
<H2 ID="name"
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
CLEAR=left|right|all|"..."
SEQNUM=nnn
SKIP=nnn
DINGBAT=entity-name
SRC="..."
MD="..."
NOWRAP>characters...
</H2>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- The specification recommends that a document use the
header elements in order, without breaks, beginning with H1.
(ed: I have not identified a browser that enforces this.)
The ID attribute is proposed in HTML+ and Version 3
to replace the NAME attribute
in the A element to establish internal hyperlink destinations.
All other attributes are proposed in Version 3.
Typical rendering is bold, large font, flush left.
Headings are Level 0 elements.
- Description
- The H3 element identifies text to be separated and displayed
less prominently than H2 but more prominently than H4.
- Minimum Attributes
<H3>characters...
</H3>
- All Possible Attributes
<H3 ID="name"
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
CLEAR=left|right|all|"..."
SEQNUM=nnn
SKIP=nnn
DINGBAT=entity-name
SRC="..."
MD="..."
NOWRAP>characters...
</H3>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- The specification recommends that a document use the
header elements in order, without breaks, beginning with H1.
(ed: I have not identified a browser that enforces this.)
The ID attribute is proposed in HTML+ and Version 3
to replace the NAME attribute
in the A element to establish internal hyperlink destinations.
All other attributes are proposed in Version 3.
Typical rendering is italic, large font, slightly indented.
Headings are Level 0 elements.
- Description
- The H4 element identifies text to be separated and displayed
less prominently than H3 but more prominently than H5.
- Minimum Attributes
<H4
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
CLEAR=left|right|all|"..."
SEQNUM=nnn
SKIP=nnn
DINGBAT=entity-name
SRC="..."
MD="..."
NOWRAP>characters...
</H4>
- All Possible Attributes
<H4 ID="name">characters...
</H4>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- The specification recommends that a document use the
header elements in order, without breaks, beginning with H1.
(ed: I have not identified a browser that enforces this.)
The ID attribute is proposed in HTML+ and Version 3
to replace the NAME attribute
in the A element to establish internal hyperlink destinations.
All other attributes are proposed in Version 3.
Typical rendering is bold, normal font, indented.
Headings are Level 0 elements.
- Description
- The H5 element identifies text to be separated and displayed
less prominently than H4 but more prominently than H6.
- Minimum Attributes
<H5>characters...
</H5>
- All Possible Attributes
<H5 ID="name"
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
CLEAR=left|right|all|"..."
SEQNUM=nnn
SKIP=nnn
DINGBAT=entity-name
SRC="..."
MD="..."
NOWRAP>characters...
</H5>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- The specification recommends that a document use the
header elements in order, without breaks, beginning with H1.
(ed: I have not identified a browser that enforces this.)
The ID attribute is proposed in HTML+ and Version 3
to replace the NAME attribute
in the A element to establish internal hyperlink destinations.
All other attributes are proposed in Version 3.
By default, Netscape uses a font size for H5 that
is smaller than default text.
For most other browsers, the font size for all headers
is at least as large as the default text.
Typical rendering is italic, normal font, indented.
Headings are Level 0 elements.
- Description
- The H6 element identifies text to be separated and displayed
less prominently than H5 but more prominently than default text.
- Minimum Attributes
<H6>characters...
</H6>
- All Possible Attributes
<H6 ID="name"
LANG="..."
CLASS="..."
ALIGN=left|center|right|justify
CLEAR=left|right|all|"..."
SEQNUM=nnn
SKIP=nnn
DINGBAT=entity-name
SRC="..."
MD="..."
NOWRAP>characters...
</H6>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
- Variations
- The specification recommends that a document use the
header elements in order, without breaks, beginning with H1.
(ed: I have not identified a browser that enforces this.)
The ID attribute is proposed in HTML+ and Version 3
to replace the NAME attribute
in the A element to establish internal hyperlink destinations.
All other attributes are proposed in Version 3.
By default, Netscape uses a font size for H6 that
is smaller than default text.
For most other browsers, the font size for all headers
is at least as large as the default text.
Typical rendering is bold, normal font, not indented.
Headings are Level 0 elements.
- Description
- The HEAD contains general information about the document.
None of the elements authorized to exist
in the contents of the HEAD are displayed;
the displayed material is found within the
BODY.
- Minimum Attributes
- All Possible Attributes
<HEAD>
</HEAD>
- Elements Allowed Within...
<TITLE>
<ISINDEX>
<BASE>
<META>
<NEXTID>
<LINK>
- Allowed In Content Of...
<HTML>
- Variations
- The HTML, HEAD, and BODY elements were introduced with
Version 2, and are currently optional, but are considered
Level 0 elements by the Version 2 standard.
Version 3 also proposes the new elements of RANGE and STYLE
as allowed within a HEAD.
- Sandia Requirements
- The HTML, HEAD and BODY elements are required.
- Description
- The HP set of elements, with n=1,2,... provided
a mechanism to highlight the characters in a phrase with
one of a set of browser defined highlight mechanisms.
- Minimum Attributes
<HPn>characters... </HPn>
- All Possible Attributes
<HPn>characters... </HPn>
- Elements Allowed Within...
-
- Allowed In Content Of...
- Variations
- The Version 2 specification has declared these elements
as obsolete.
- Description
- The HR element produces a separated horizontal dividing line
drawn completely across the screen.
- Minimum Attributes
<HR>
- All Possible Attributes
<HR
ID="..."
CLASS="..."
CLEAR=left|right|all|"..."
SRC="..."
MD="..."
SIZE=number
WIDTH=number|percent
ALIGN=left|right|center
NOSHADE>
- Elements Allowed Within...
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<FORM>
<PRE>
- Variations
- The ID, CLASS, CLEAR, SRC, and MD attributes are proposed in Version 3.
SRC is proposed to specify a custom image for the rule.
Some browsers draw the line only within the current text margins
(which may be indented on left and/or right due to lists, etc.)
SIZE, WIDTH, ALIGN, and NOSHADE attributes are Netscape extensions.
The HR element is Level 0.
- Description
- The HTML element is intended to bracket the entire HTML text in
the document. All other HTML elements are inside the start and end
of the HTML element.
- Minimum Attributes
- All Possible Attributes
<HTML>
</HTML>
- Elements Allowed Within...
<HEAD>
<BODY>
- Allowed In Content Of...
- Variations
- The HTML, HEAD, and BODY elements were introduced with
Version 2, and are currently optional, but are considered
Level 0 elements by the Version 2 standard.
- Sandia Requirements
- The HTML, HEAD and BODY elements are required.
- Description
- The I element changes the physical rendering of the
contents of the element to an italics (or slanted) font.
- Minimum Attributes
<I>characters...
</I>
- All Possible Attributes
<I
ID="..."
LANG="..."
CLASS="...">characters...
</I>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The IMG element allows an image file to be inserted within
an HTML document along with the text.
The ALT attribute defines text that will be displayed if the image
is not or cannot be displayed by the browser.
The ALT text can contain
special characters,
but it cannot contain markup.
The SRC attribute identifies a URL for retrieving the image.
The ISMAP attribute is only meaningful if the IMG element is
within the contents of an A element, and a responding cgi-bin program
has been established at the URL identified by the HREF attribute
of the A element.
If a single A element spans both an image and text,
the cgi-bin program will receive the HREF input values, if any,
if the text is selected, or the x,y cursor coordinates if the image is selected.
For references to this advanced feature, see
Acknowledgements.
- Minimum Attributes
<IMG SRC="...">
- All Possible Attributes
<IMG SRC="..."
ALT="..."
ISMAP
ID="..."
LANG="..."
CLASS="..."
MD="..."
ALIGN=bottom|middle|top|left|right|texttop|absmiddle|baseline|absbottom
HEIGHT=value
WIDTH=value
UNITS="..."
BORDER=value
LOWSRC="..."
HSPACE=value
VSPACE=value>
- Elements Allowed Within...
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- The attributes BORDER, HEIGHT, WIDTH, HSPACE, VSPACE, and LOWSRC
are Netscape extensions.
Version 3 proposes adding the WIDTH and HEIGHT attributes.
Version 1 defines only
bottom|middle|top
as values for the ALIGN attribute.
The additional values for the ALIGN attribute are Netscape extensions,
and include the capability to define floating images.
Version 3 proposes adding only the (LEFT|RIGHT) values for ALIGN
to identify images that imply that text can float around the image.
Some image capable browsers will display the ALT
text until the full image is retrieved.
The Version 2 specification states that
Level 0 conformance must accept the element, but Level 1
conformance is required before it displays the image.
Version 3 proposes the generalized attributes ID, LANG, CLASS, and MD.
In addition, it adds the UNITS attribute for use by the WIDTH and HEIGHT
attributes to define units other than pixels.
Version 3 proposes a FIG element
as an advanced alternative to the IMG element,
for more sophisticated multi-part overlay images,
more control over text that is the equivalent of ALT,
and with the proposed SHAPE attribute on the A element
a method to perform the common use of the ISMAP attribute
without the need for a responding cgi-bin program.
- Sandia Requirements
- The ALT attribute and a value describing the image is required.
If known, the BORDER, HEIGHT, and WIDTH attributes are recommended
as they improve download performance on some browsers.
If used, the HEIGHT and WIDTH attributes shall specify the actual
size of the stored image in pixels.
- Description
- The INPUT element is used to specify a simple input field
as part of the contents in a FORM element.
TYPE=text is default.
NAME defines the symbolic name of the field
returned to the server on submission and must be present
for all but TYPE=submit|reset.
For TYPE=checkbox|radio, multiple INPUT elements may have the same NAME value.
VALUE is used to specify a default.
For TYPE=text|password VALUE defines default text to be returned,
which normally is null.
For TYPE=checkbox|radio VALUE defines the value returned when the
checkbox or radio is selected, which normally is "on".
For TYPE=submit|reset VALUE defines the label for the pushbutton.
CHECKED defaults the checkbox or radio to selected.
SIZE and MAXLENGTH are only
used with TYPE=text|password.
SIZE is the physical size of the
displayed input field expressed in characters
or characters,rows.
MAXLENGTH is the maximum number of characters that are
accepted as input.
- Minimum Attributes
<INPUT>
- All Possible Attributes
<INPUT TYPE=type
ID="..."
LANG="..."
CLASS="..."
NAME="..."
VALUE="..."
DISABLED
ERROR="..."
SRC="..."
MD="..."
CHECKED
SIZE="..."
MAXLENGTH="..."
MIN=number
MAX=number
ALIGN=top|middle|bottom|left|right
ACCEPT="...">
- Elements Allowed Within...
- Allowed In Content Of...
<FORM>
- Variations
- Version 2 defines the TYPE attribute values of
text|password|checkbox|radio|submit|reset|hidden|image
The <TEXTAREA> element
should be used instead of this INPUT element for multiline input areas.
TYPE=hidden VALUE="..." is recognized by some browsers, and is
used to submit fixed information not entered by the user.
TYPE=image was introduced in Version 2 and specifies
an image, identified by the URL
with the new SRC attribute,
which, when clicked, performs the submission and sends
the X,Y coordinates of the click, similar to ISMAP in the IMG element.
Version 2 sets a max limit of 1024 characters on VALUE.
Version 3 proposes the additional TYPE attribute values of
range|file|scribble.
Version 3 proposes the additional ID, LANG, CLASS, DISABLED, ERROR,
MIN, MAX, ACCEPT, and MD attributes.
The Version 3 proposed TYPE=range
uses the proposed MIN and MAX attributes to specify limits to
numeric (real or integer) input.
The proposed default value is halfway between MIN and MAX.
The Version 3 proposed TYPE=file
permits attaching a file to the submitted output.
Version 3 proposes that multiple INPUT elements with TYPE=file
would be permitted for attaching multiple files.
The ACCEPT attribute is proposed to be used to specify
a comma separated list of MIME content types of the attached files.
The Version 3 proposed TYPE=scribble
is to allow the user to scribble with a pointing device on top of
the image specified with the SRC attribute.
The Version 3 proposed DISABLED attribute would display this INPUT,
but prohibit user entry/modification.
The Version 3 proposed ERROR attribute defines text to be displayed
in the event that the entered value for this INPUT is invalid.
All elements concerning FORM are Level 2.
- Description
- The INS element
changes the character rendering of the
contents of the element to logically represent
inserted text, for instance in modifications in legal documents.
- Minimum Attributes
<INS>characters... </INS>
- All Possible Attributes
<INS
ID="..."
LANG="..."
CLASS="...">characters...
</INS>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The INS element is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- This element appears to be a precursor to the
<FORM> element which has more features.
When placed in the BODY of the document,
it requires the ACTION attribute to point to a cgi-bin
program which can handle the query, and
produces a simple INPUT field with a prompt
of: "This is a searchable index. Enter search keywords:"
When placed in the HEAD of the document, it
informs the browser that the document is an index
document and can be examined using a keyword search.
The ISINDEX element is usually generated
automatically by a server-side script.
- Minimum Attributes
<ISINDEX>
- All Possible Attributes
<ISINDEX
ACTION="..."
PROMPT="...">
- Elements Allowed Within...
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<HEAD>
<LI>
- Variations
- The PROMPT attribute is a Netscape extension.
ISINDEX is a Level 0 element.
The new, more sophisticated
FORM
element is now used more widely.
Version 2 describes ISINDEX as a Level 0 element as part of the HEAD.
It does not include it as part of the BODY.
Version 3 proposes the PROMPT attribute.
- Description
- The KBD element changes the character rendering of the
contents of the element to logically represent
text entered as keyboard input.
- Minimum Attributes
<KBD>characters...
</KBD>
- All Possible Attributes
<KBD
ID="..."
LANG="..."
CLASS="...">characters...
</KBD>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- While intended to be distinguishable from CODE, so that
input and output would be different, most browsers render
this the same as CODE, simply as a fixed-width font.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The LANG element is used to change the LANG context from
the current context.
- Minimum Attributes
<LANG>characters... </LANG>
- All Possible Attributes
<LANG
ID="..."
CLASS="...">characters...
</LANG>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The LANG element is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- The LH element defines a list header used as a title for a list.
Browsers can use this in place of the full list when a mechanism
is provided to fold and unfold nested lists.
- Minimum Attributes
<LH>characters...
</LH>
- All Possible Attributes
<LH
ID="..."
LANG="..."
CLASS="...">characters...
</LH>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<DL>
<OL>
<UL>
- Variations
- The LH element is proposed in Version 3 as an optional element
at the beginning of lists. It is expected that browsers may
render this element in a different style/font than the list itself.
- Description
- The LI element defines a list item.
It is rendered differently depending upon the list within which
it appears.
- Minimum Attributes
<LI>characters...
- All Possible Attributes
<LI
within UL TYPE=disk|circle|square
within OL TYPE=A|a|I|i|i
within OL VALUE=n>characters...</LI>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
<P>
<UL>
<OL>
<DIR>
<MENU>
<DL>
<PRE>
<BLOCKQUOTE>
<FORM>
<ISINDEX>
- Allowed In Content Of...
<DIR>
<MENU>
<OL>
<UL>
- Variations
- TYPE and VALUE attributes are Netscape extensions.
Most browsers assume the list item ends with the beginning
of the next list item or the end of the list and
do not require the closing tag
</LI>
All list elements are Level 0.
- Description
- The LINK element is used to indicate a relationship between
this document and other documents or objects.
Multiple LINK elements may exist in a document.
A LINK in document A with an HREF to document/object B with
REL=relation
identifies a relationship that B has to A that A recognizes/authorizes/verifies.
A LINK in document B with an HREF to document/object A with
REV=relation that is the identical relation
identifies a desired/expected/claimed relationship of B to document/object A,
but must be verified by checking with A.
For further description of the LINK attributes, see the
A element.
- Minimum Attributes
<LINK HREF="..."
>
- All Possible Attributes
<LINK HREF="..."
REL="..."
REV="..."
URN="..."
TITLE="..."
METHODS="..."
>
- Elements Allowed Within...
- Allowed In Content Of...
<HEAD>
- Variations
- LINK is a Level 0 element.
In addition to those mentioned with the A element,
Version 3 reserves some relations for REL that are expected to
be used for document specific toolbars. Currently these include
Home, ToC, Index, Glossary, Copyright, Up, Next,
Previous, Help, Bookmark.
Version 3 also discusses relations for a document banner
and style sheets.
- Sandia Requirements
- A LINK element in the HEAD to identify the owner of
the document responsible for its accuracy is
required by Sandia's automated Web tools:
<LINK REV="owns" TITLE="Full Name" HREF="mailto:owner-e-mail@sandia.gov">
LINK elements are also recommended to identify
other individuals and their relationships to this document.
The REV value of made should be used to identify the
author of the document.
Suggested values for REV in additional LINK elements are:
approves, editor, publisher.
Large documents which are separated into smaller HTML subdocuments
should use the LINK element with the REL attribute to identify these
relationships.
The parent document should identify all subdocuments by:
<LINK REL="Subdocument" TITLE="Subdoc Name" HREF="link-url">
The subdocument may identify its parent by:
<LINK REV="Subdocument" TITLE="Maindoc Name" HREF="link-url">
Any Sandia document which is part of
a set of HTML subdocuments which form a sequence or hierarchy should
include two specific LINK elements identifying the REL values of
next and previous.
Only one next and one previous relationship
may be specified in a document.
Any of the other document relationships mentioned in this Reference Manual
may also be used.
- Description
- The LISTING element defined a separated multi-line set of text
to be rendered as it exists in the source document with
the same line breaks.
- Minimum Attributes
<LISTING>characters...
</LISTING>
- All Possible Attributes
<LISTING WIDTH="..."
>characters...
</LISTING>
- Elements Allowed Within...
<A>
<HR>
<BR>
<TT>
<B>
<I>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- Most browsers use fixed-width characters for LISTING text.
This element existed in Version 0 and has been replaced by the
<PRE> element.
Version 2 of the standard has declared LISTING as obsolete
and some current browsers no longer recognize it.
- Description
- The MENU element defines an unordered list consisting of a number of
separated multi-line
<LI> elements which
may or may not be marked by a bullet or similar symbol.
Similar to the <UL> element, it is rendered
in a more compact manner.
-
- Minimum Attributes
<MENU></MENU>
- All Possible Attributes
<MENU COMPACT>
</MENU>
- Elements Allowed Within...
<LI>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- This list type is often rendered identically to UL.
The COMPACT attribute of the UL element is more often used than
this MENU element.
By adding the PLAIN attribute to eliminate the bullets to the
UL element, Version 3 proposes to remove the MENU element.
All list elements are Level 0.
- Description
- The META element is used within the HEAD element
to embed document meta-information not defined
by other HTML elements.
Such information may be extracted by servers/browsers.
The HTTP-EQUIV attribute binds the element to an HTTP response header.
If not present, the NAME attribute should be used to identify this
meta-information and it should not be used within an HTTP response header.
If the NAME attribute is not present, the name can be assumed equal to
the value of HTTP-EQUIV.
The CONTENT attribute defines
the meta-information content to be associated with the given name
and/or HTTP response header.
- Minimum Attributes
<META CONTENT="..."
>
- All Possible Attributes
<META HTTP-EQUIV="..."
NAME="..."
CONTENT="..."
URL="..."
>
- Elements Allowed Within...
- Allowed In Content Of...
<HEAD>
- Variations
- The META element was introduced in Version 2 and is a
Level 1 element.
Netscape 1.1 has added a automatic refresh capability using the META element
by setting the HTTP-EQUIV attribute to
"REFRESH",
the CONTENT attribute to a number of seconds, and the URL attribute
to the file to load which defaults to reloading the same file.
The URL attribute is a Netscape extension.
Netscape 1.1 also recognizes placing the URL inside the quotes
which define the CONTENT value
by using a semicolon following the number of seconds, then the
URL=http://... text.
- Sandia Requirements
- Two META elements are required to identify specific
information for Sandia's automated Web tools.
<META NAME="REVIEW" CONTENT="DD MMM YYYY">
<META HTTP-EQUIV="KEYWORDS" CONTENT="key1, key2, key3">
For large documents split into multiple HTML subdocuments, these META
elements should only be included in the HTML document that is the parent
of all the subdocuments, usually the Introduction or Table of Contents document.
- Description
- The single attribute
N=
provides the next available identifier
for use by automatic hypertext editors.
If the NEXTID element is manually entered, it should be
alphabetical to avoid conflict with such editors.
- Minimum Attributes
<NEXTID N="..."
>
- All Possible Attributes
<NEXTID N="..."
>
- Elements Allowed Within...
- Allowed In Content Of...
<HEAD>
- Variations
- NEXTID is a Level 0 element.
- Description
- All text between the start and end of the
NOBR elements
cannot have line breaks inserted between them.
- Minimum Attributes
<NOBR>characters... </NOBR>
- All Possible Attributes
<NOBR>characters... </NOBR>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The NOBR element is a Netscape extension.
- Description
- The NOTE element changes the rendering of the
contents of the element to logically represent
separated notational text.
The SRC attribute specifies an image to appear preceding the note.
- Minimum Attributes
<NOTE>characters... </NOTE>
- All Possible Attributes
<NOTE
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
SRC="..."
MD="..."</NOTE>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The NOTE element is a Version 3 proposed element.
It is expected to typically be rendered indented, without a preceding
bullet, symbol, or other graphic. Accompanying style guides are
expected to define renderings associated with specific CLASS values.
NOTE, CAUTION, and WARNING are expected values for the CLASS attribute.
- Description
- The OL element defines an ordered list consisting of a number of
separated multi-line
<LI> elements, and
ordered numerically in some way.
- Minimum Attributes
<OL></OL>
- All Possible Attributes
<OL
COMPACT
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
CONTINUE
SEQNUM=value
START=value
TYPE=A|a|I|i|1></OL>
- Elements Allowed Within...
<LH>
<LI>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- Version 3 proposes the general ID, LANG, CLASS, and CLEAR attributes.
The CONTINUE attribute is proposed by Version 3 to continue the
numbering from where the previous OL list left off.
The SEQNUM attribute is proposed by Version 3 to
define a starting number for the list.
START is a Netscape extension to do the same thing as SEQNUM.
The TYPE attribute is a Netscape extension.
Version 3 proposes using associated style sheets and the CLASS attribute
to handle these, and other, options to numbering style.
All list elements are Level 0.
- Description
- The OPTION element identifies a choice in a SELECT element,
which in turn is part of the contents of a FORM element.
SELECTED specifies that this option is selected by default.
If SELECT allows MULTIPLE, then multiple options may be SELECTED.
If the VALUE attribute it not present and the OPTION is selected,
the OPTION contents is returned upon submission of the FORM.
If the VALUE attribute is present and the OPTION is selected,
the value of the VALUE attribute is returned instead of the contents.
- Minimum Attributes
<OPTION>characters...
- All Possible Attributes
<OPTION SELECTED DISABLED VALUE="..."
ID="..."
LANG="..."
CLASS="..."
ERROR="..."
SHAPE="..."
>characters...
</OPTION>
- Elements Allowed Within...
- Allowed In Content Of...
<SELECT>
- Variations
- The DISABLED attribute was first proposed with Version 2,
is also defined in Version 3, and
would display this OPTION, but prohibit user selection/deselection.
Version 2 sets a max limit of 1024 characters on VALUE.
Version 3 proposes the ID, LANG, CLASS, ERROR, and SHAPE attributes.
The Version 3 proposed ERROR attribute defines text to be displayed
in the event that selectiing this OPTION is invalid.
The Version 3 proposed SHAPE attribute defines the shape of the
"hotspot" on the imgage defined by the SRC attribute
of the surrounding SELECT element.
The proposed values of SHAPE are:
"default", "circle x,y,r",
"rect x,y,w,h", and
"polygon x1,y1,x2,y2,...".
All elements concerning FORM are Level 2.
- Description
- The OVERLAY element is used to overlay one or more images
on top of a FIG image.
The X and Y attributes identify the offsets from the top left
of the FIG where the top left of the overlay will be placed.
- Minimum Attributes
<OVERLAY SRC="...">
- All Possible Attributes
<OVERLAY SRC="..."
MD="..."
UNITS=pixels|en
X=value
Y=value
WIDTH=value
HEIGHT=value
IMAGEMAP="...">
- Elements Allowed Within...
- Allowed In Content Of...
<FIG>
- Variations
- The OVERLAY element is proposed in Version 3 as part of
the FIG construct.
It is designed to take advantage of the caching system of most browsers
for a series of similar images which may only differ by an overlay
and the rest is already in cache.
- Description
- The P element is used to denote a paragraph break,
and separates two blocks of text.
Many other elements automatically imply a text separation,
such as headings, list elements, blockquotes, etc.
- Minimum Attributes
<P>characters...
- All Possible Attributes
<P
ID="name"
ALIGN=center|left|right|justify|indent
WRAP=on|off
NOWRAP
CLEAR=left|right|all|"..."
LANG="..."
CLASS="...">characters...
</P>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<ADDRESS>
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- In Version 1, the
<P> element was a separator
and the </P> element was not defined.
Version 2 changed the concept to a container and introduced the
optional </P> element.
HTML+ introduced the ID and ALIGN attributes.
The ID attribute is proposed in HTML+ to replace the NAME attribute
in the A element to establish internal hyperlink destinations,
and ALIGN would define the alignment of the text within the paragraph.
Version 3 keeps the optional </P> element and
both the ID and ALIGN elements, but
Version 3 does not currently include indent as an option
for ALIGN.
WRAP would turn off automatic word wrap, leaving text as
it appears in the source.
Version 3 replaces the WRAP attribute and values with the NOWRAP attribute.
The P element is Level 0.
- Description
- The PERSON element
changes the character rendering of the
contents of the element to logically represent
the name of people
to allow these to be extracted automatically by indexing programs.
- Minimum Attributes
<PERSON>characters... </PERSON>
- All Possible Attributes
<PERSON
ID="..."
LANG="..."
CLASS="...">characters...
</PERSON>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The PERSON element is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- The PLAINTEXT element defined a separated multi-line set of text
to be rendered as it exists in the source document with
the same line breaks. It was designed to ignore all subsequent
HTML tags. Therefore, it was always last in a document, allowing
the remainder of the document to be presented as text.
- Minimum Attributes
<PLAINTEXT>characters...
</PLAINTEXT>
- All Possible Attributes
<PLAINTEXT WIDTH="..."
>characters...
</PLAINTEXT>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- Most browsers use fixed-width characters for PLAINTEXT text.
A few browsers accepted the ending tag, which meant that
the ending tag could not exist in the text.
This element existed in Version 0 and has been replaced by the
<PRE> element.
Version 2 of the standard has declared PLAINTEXT as obsolete
and some current browsers no longer recognize it.
- Description
- The PRE element defines a separated multi-line set of text
to be rendered as it exists in the source document with
the same line breaks and spaces.
Normal text removes multiple spaces and line breaks in the source.
- Minimum Attributes
<PRE>characters...
</PRE>
- All Possible Attributes
<PRE WIDTH="..."
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
>characters...
</PRE>
- Elements Allowed Within...
<A>
<HR>
<BR>
<TT>
<B>
<I>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- Most browsers use fixed-width characters for PRE text.
The Version 2 specification states that the tab character should
position to the next 8 character boundary.
Version 3 encourages using the proposed TAB element instead.
One typical use of PRE has been for tables, but the Version 3
TABLE element is proposed to fulfill that requirement.
The ID, LANG, CLASS, and CLEAR attributes are proposed in Version 3.
The attribute WIDTH has been alternatively identified as the
maximum number of characters that can be displayed on a single line
and the minimum number of characters that the browser should
try to insure are displayed on a single line, possibly by selecting
a smaller font size.
Many browsers ignore the WIDTH attribute, and Version 3 is discussing
the possibility of removing it.
The PRE element is Level 0.
- Description
- The Q element
changes the character rendering of the
contents of the element to logically represent a
short quotation.
- Minimum Attributes
<Q>characters... </Q>
- All Possible Attributes
<Q
ID="..."
LANG="..."
CLASS="...">characters...
</Q>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The Q element is typically shown enclosed in quotations marks
as appropriate to the LANG language context.
It is a Version 3 proposed element.
All character definition elements are Level 2.
- Description
- The S element changes the physical rendering of the
contents of the element to a font
with a strikeout line through the letters.
- Minimum Attributes
<S>characters...
</S>
- All Possible Attributes
<S
ID="..."
LANG="..."
CLASS="...">characters...
</S>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The S element is proposed in Version 3.
This replaces the STRIKE element which was proposed in Version 2.
All character definition elements are Level 2.
- Description
- The SAMP element changes the character rendering of the
contents of the element to logically represent a sequence of literal characters.
- Minimum Attributes
<SAMP>characters...
</SAMP>
- All Possible Attributes
<SAMP
ID="..."
LANG="..."
CLASS="...">characters...
</SAMP>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- This is usually rendered with a fixed-width font.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The SELECT element defines a menu of a series of selectable
input in a FORM, each identified with the OPTION element.
At least one OPTION element is expected within the SELECT contents.
NAME is the symbolic name of the field
returned to the server on submission.
SIZE determines the number of OPTIONS physically visible
when the browser displays the FORM.
The default selection will be the first OPTION in the SELECT contents.
The MULTIPLE attribute, if present, allows multiple selections, and
causes no OPTION to be the default.
- Minimum Attributes
<SELECT NAME="...">characters...
</SELECT>
- All Possible Attributes
<SELECT NAME="..."
SIZE=value
MULTIPLE
ID="..."
LANG="..."
CLASS="..."
ALIGN=top|middle|bottom|left|right
DISABLED
ERROR="..."
SRC="..."
MD="..."
WIDTH=value
HEIGHT=value
UNITS=pixels|em>characters...
</SELECT>
- Elements Allowed Within...
<OPTION>
- Allowed In Content Of...
<FORM>
- Variations
- The ERROR attribute without a value was first introduced
with Version 2 and is not widely implemented.
Version 3 proposes the ID, LANG, CLASS, ALIGN, DISABLED,
ERROR (with a value), SRC, MD, WIDTH, HEIGHT, and UNITS attributes.
The Version 3 proposed DISABLED attribute would display this menu,
but prohibit user entry/modification.
The Version 3 proposed ERROR attribute defines text to be displayed
in the event that the current selections for this menu are invalid.
Version 3 proposes a SRC attribute to identify a URL for an image
to be displayed instead of the OPTION texts for this menu,
with each OPTION element identifying its "hotspot" on this image.
If SRC is present, the texts would only be used for non-graphical browsers.
All elements concerning FORM are Level 2.
- Description
- The SMALL element changes the physical rendering of the
contents of the element to a smaller font than normal text, if practical.
- Minimum Attributes
<SMALL>characters...
</SMALL>
- All Possible Attributes
<SMALL
ID="..."
LANG="..."
CLASS="...">characters...
</SMALL>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The SMALL element is proposed in Version 3.
All character definition elements are Level 2.
- Description
- The STRIKE element changes the physical rendering of the
contents of the element to a font
with a strikeout line through the letters.
- Minimum Attributes
<STRIKE>characters...
</STRIKE>
- All Possible Attributes
<STRIKE>characters...
</STRIKE>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- This is a Version 2 proposed element.
(ed: This appears to be an undocumented extension which
works in Netscape. Anyone try this with other browsers?)
This is replaced in Version 3 with the <S> element.
- Description
- The STRONG element changes the character rendering of the
contents of the element to logically strengthen the text.
- Minimum Attributes
<STRONG>characters...
</STRONG>
- All Possible Attributes
<STRONG
ID="..."
LANG="..."
CLASS="...">characters...
</STRONG>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- This is usually rendered as bold.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The SUB element changes the physical rendering of the
contents of the element to a subscripted position.
- Minimum Attributes
<SUB>characters...
</SUB>
- All Possible Attributes
<SUB
ID="..."
LANG="..."
CLASS="...">characters...
</SUB>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The SUB element is proposed in Version 2.
No font size change was implied in Version 2, but Version 3
states that the font size shall be smaller than normal, if practical.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The SUP element changes the physical rendering of the
contents of the element to a superscripted position.
- Minimum Attributes
<SUP>characters...
</SUP>
- All Possible Attributes
<SUP
ID="..."
LANG="..."
CLASS="...">characters...
</SUP>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The SUP element is proposed in Version 2.
No font size change was implied in Version 2, but Version 3
states that the font size shall be smaller than normal, if practical.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The TAB element aligns the following text according to
a defined horizontal position.
A TAB position can be defined by the ID attribute.
Text is positioned using the TO and/or ALIGN attributes, or
the INDENT attribute.
- Minimum Attributes
<TAB>characters...
- All Possible Attributes
<TAB
ID="..."
INDENT=ens
TO="..."
ALIGN=left|center|right|decimal
DP="...">characters...
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The TAB element is proposed in Version 3.
- Description
- The TABLE element defines a series of rows of table cell elements.
The contents of the TABLE element expects an optional
CAPTION element, followed by a series of
TR elements, which in turn are followed by
a series of optional TH header elements and/or
TD data elements.
- Minimum Attributes
<TABLE></TABLE>
- All Possible Attributes
<TABLE
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
NOFLOW
ALIGN=left|right|center|justify|bleedleft|bleedright
UNITS=en|relative|pixels
COLSPEC="..."
DP="..."
WIDTH=value
BORDER=value
NOWRAP></TABLE>
- Elements Allowed Within...
<CAPTION>
<TR>
<TABLE>
-others TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The TABLE element is proposed in Version 3.
Consistent with the nature of HTML, it defines the logical contents
of cells and their row/column location, rather than a physical layout
which is left as a function of the browser.
Details of the appearence of the table,
along with the size of margins around cells, even perhaps ruling and shading,
might be controlled by associated style sheets, proposed in Version 3.
This element is an extension in Netscape 1.1.
Having a value possible for the BORDER attribute is a Netscape extension.
The attributes CELLSPACING and CELLPADDING are Netscape extensions.
(ed.The exact behavior caused by the WIDTH appears to be different
in the description of Version 3 and Netscape.)
- Description
- The TD element defines a data cell as part of the TABLE construct.
- Minimum Attributes
<TD>
- All Possible Attributes
<TD
ID="..."
LANG="..."
CLASS="..."
COLSPAN=value
ROWSPAN=value
ALIGN=left|right|center|justify|decimal
DP="..."
VALIGN=top|middle|bottom|baseline
NOWRAP
AXIS="..."
AXES="..."
WIDTH=value>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<TABLE>
- Variations
- The TD element is proposed in Version 3 as part of the TABLE construct.
A browser is to assume the table cell ends with the beginning
of the next table cell or the beginning of another table row
or the end of the table and thus a closing tag is not defined.
This element is an extension in Netscape 1.1.
The values
justify|decimal for the ALIGN attribute
do not yet exist in Netscape.
The WIDTH attribute is a Netscape extension.
- Description
- The TEXTAREA element is used to specify a multiline input field
as part of the contents in a FORM element.
NAME defines the symbolic name of the field
returned to the server on submission.
The characters between the opening and closing tags
define the text to be initially displayed in the textarea,
and the default text to be returned, normally null.
Only ASCII text is allowed as characters, and newlines are respected.
ROWS and COLS
define the physical size of the
displayed input field in numbers of characters.
- Minimum Attributes
<TEXTAREA NAME="..."
ROWS="..."
COLS="...">
</TEXTAREA>
- All Possible Attributes
<TEXTAREA NAME="..."
ROWS="..."
COLS="..."
ID="..."
LANG="..."
CLASS="..."
ALIGN=top|middle|bottom|left|right
DISABLED
ERROR="...">characters...
</TEXTAREA>
- Elements Allowed Within...
- Allowed In Content Of...
<FORM>
- Variations
- Version 3 proposes the
ID, LANG, CLASS, ALIGN, DISABLED, and ERROR attributes.
The Version 3 proposed DISABLED attribute would display this TEXTAREA,
but prohibit user entry/modification.
The Version 3 proposed ERROR attribute defines text to be displayed
in the event that the entered value for this TEXTAREA is invalid.
All elements concerning FORM are Level 2.
- Description
- The TH element defines a header cell as part of the TABLE construct.
The browser should render the table to cause some difference between
TH elements and TD elements.
- Minimum Attributes
<TH>
- All Possible Attributes
<TH
ID="..."
LANG="..."
CLASS="..."
COLSPAN=value
ROWSPAN=value
ALIGN=left|right|center|justify|decimal
DP="..."
VALIGN=top|middle|bottom|baseline
NOWRAP
AXIS="..."
AXES="..."
WIDTH=value>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
<TABLE>
- Variations
- The TH element is proposed in Version 3 as part of the TABLE construct.
A browser is to assume the table cell ends with the beginning
of the next table cell or the beginning of another table row
or the end of the table and thus a closing tag is not defined.
This element is an extension in Netscape 1.1.
The values
justify|decimal for the ALIGN attribute
do not yet exist in Netscape.
The WIDTH attribute is a Netscape extension.
Netscape renders TH elements in a bold font, but otherwise identical
to TD elements.
- Description
- The TITLE is not part of the document text.
Often the title is used by a browser to label the display window.
Some Web search engines only search the title of Web pages.
Therefore the text of the TITLE should be kept short
(usually less than 64 characters)
but sufficient to identify the document.
- Minimum Attributes
<TITLE>characters...
</TITLE>
- All Possible Attributes
<TITLE>characters...
</TITLE>
- Elements Allowed Within...
- Allowed In Content Of...
<HEAD>
- Variations
- Some browsers will truncate titles to a length they can handle.
TITLE is a Level 0 element.
- Sandia Requirements
- The TITLE element is required to include a short, uniquely
descriptive document title.
- Description
- The TR element defines a row as part of the TABLE construct.
The contents of the TR element is expected to contain at least one
of either the TH element or the TD element.
- Minimum Attributes
<TR>
- All Possible Attributes
<TR
ID="..."
LANG="..."
CLASS="..."
ALIGN=left|right|center|justify|decimal
DP="..."
VALIGN=top|middle|bottom|baseline
NOWRAP>
- Elements Allowed Within...
<TD>
<TH>
-others TBD-
- Allowed In Content Of...
<TABLE>
- Variations
- The TR element is proposed in Version 3.
A browser is to assume the table row ends with the beginning
of the next table row or the end of the table and
thus a closing tag is not defined.
Version 3 proposes that browsers should tolerate the absence of
the first TR in a table.
This element is an extension in Netscape 1.1.
The values
justify|decimal for the ALIGN attribute
do not yet exist in Netscape.
- Description
- The TT element changes the physical rendering of the
contents of the element to a fixed width typewriter font.
- Minimum Attributes
<TT>characters...
</TT>
- All Possible Attributes
<TT
ID="..."
LANG="..."
CLASS="...">characters...
</TT>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The U element changes the physical rendering of the
contents of the element to an underlined font.
- Minimum Attributes
<U>characters... </U>
- All Possible Attributes
<U
ID="..."
LANG="..."
CLASS="...">characters...
</U>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- The U element is proposed in the Version 2 specification
but is not widely implemented.
The ID, LANG, and CLASS attributes are proposed in Version 3.
It is often rendered in italic or slanted rather than underlined.
All character definition elements are Level 2.
- Description
- The UL element defines an unordered list consisting of a number of
separated multi-line
<LI> elements, and usually
marked by a bullet or similar symbol.
- Minimum Attributes
<UL></UL>
- All Possible Attributes
<UL
COMPACT
ID="..."
LANG="..."
CLASS="..."
CLEAR=left|right|all|"..."
PLAIN
SRC="..."
MD="..."
DINGBAT="..."
WRAP=vert|horiz
TYPE=disk|circle|square>
</UL>
- Elements Allowed Within...
<LH>
<LI>
- Allowed In Content Of...
<BLOCKQUOTE>
<BODY>
<DD>
<FORM>
<LI>
- Variations
- Nested UL lists are usually rendered more indented with
differing bullets or symbols.
Version 3 proposes the ID, LANG, CLASS, CLEAR, PLAIN,
SRC, MD, DINGBAT, and WRAP attributes.
The TYPE attribute is a current Netscape extension.
Version 3 proposes to replace it with the SRC and DINGBAT attributes
to point to general server and browser images respectively.
Specifying
<UL PLAIN> to eliminate the bullets
is proposed by Version 3 as a replacement for the
MENU element.
Specifying <UL PLAIN WRAP=HORIZ> is proposed
by Version 3 as a replacement for the DIR element.
The browser may dynamically determine the appropriate number of columns.
All list elements are Level 0.
- Description
- The VAR element changes the character rendering of the
contents of the element to logically represent a variable name.
- Minimum Attributes
<VAR>characters...
</VAR>
- All Possible Attributes
<VAR
ID="..."
LANG="..."
CLASS="...">characters...
</VAR>
- Elements Allowed Within...
<A>
<IMG>
<BR>
<EM>
<STRONG>
<CODE>
<SAMP>
<KBD>
<VAR>
<CITE>
<TT>
<B>
<I>
- Allowed In Content Of...
<A>
<ADDRESS>
<B>
<CITE>
<CODE>
<DD>
<DT>
<EM>
<H1>
<H2>
<H3>
<H4>
<H5>
<H6>
<I>
<KBD>
<LI>
<P>
<PRE>
<SAMP>
<STRONG>
<TT>
<VAR>
- Variations
- This is usually rendered in italics.
The ID, LANG, and CLASS attributes are proposed in Version 3.
All character definition elements are Level 2.
- Description
- The WBR element exists to force the possibility of a word break
in a no-break section.
- Minimum Attributes
<WBR>
- All Possible Attributes
<WBR>
- Elements Allowed Within...
- Allowed In Content Of...
<NOBR>
- Variations
- The NOBR element is a Netscape extension.
- Description
- The XMP element defined a separated multi-line set of text
to be rendered as it exists in the source document with
the same line breaks.
- Minimum Attributes
<XMP>characters...
</XMP>
- All Possible Attributes
<XMP WIDTH="..."
>characters...
</XMP>
- Elements Allowed Within...
-TBD-
- Allowed In Content Of...
-TBD-
- Variations
- Most browsers use fixed-width characters for XMP text.
This element existed in Version 0 and has been replaced by the
<PRE> element.
Version 2 of the standard has declared XMP as obsolete
and some current browsers no longer recognize it.
- Description
- Uniform Resource Locators (URL) let you specify how to reach an
Internet resource. They consist of four basic parts:
aaaa://bbb.bbb.bbb/ccc/ccc/ccc?ddd
aaaa: The access method.
- This specifies the mechanism to be used by the browser
to communicate with the resource.
Mechanism codes must be registered to be widely recognized.
An X500 mechanism, as well as WHOIS, and Network Database mechanisms
are under study.
Currently recogized mechanisms include:
http: HyperText Transfer Protocol
- This is the most commonly used access method. It requires
a program running on the destination computer that understands
and responds to this protocol. The file retrieved might be
an HTML file, a graphic file, a sound file, an animation sequence file,
a file to be executed by the server (e.g. cgi-bin files),
or a word processing file. Whether the file retrieved can be
handled depends on the browser.
https: HyperText Transfer Protocol
- This is a variation on the standard access method.
(ed: I am still researching/working on this definition.)
file: Local File Access
- This method causes the browser to load a file from the
locally accessible disk system. This is commonly used to
preview Web pages being developed on a computer that has
a browser, but does not have a server.
ftp: File Transport Protocol
- This method uses normal Internet FTP to retrieve
a file. Most browsers will ask for a location/name on the local
disk system to store the file.
mailto: E-Mail Form
- The argument following the access code is the destination e-mail address.
If the browser understands this access code, the browser will automatically
generate an input FORM for entering the e-mail message. It may also
accept additional arguments for default "Subject:" etc.
Most Version 2 browsers now handle this access code.
Note that any special characters in an e-mail address (e.g. "%")
must be URL converted (e.g. "%25")
news: USENET News
- Only argument following the access code is the group or article name.
nntp: Local Network News Transport Protocol
- --TBD--
wais: Wide Area Information Servers
- --TBD--
gopher: GOPHER
- --TBD--
telnet: TELNET
- The arguments following the access code are the login arguments
to the telnet session as
user[:password]@host.
cid: Content identifiers for MIME body part
- --TBD--
mid: Message identifiers for electronic mail
- --TBD--
afs: AFS File Access
- --TBD--
prospero: Prospero Link
- --TBD--
x-exec: Executable Program
- --TBD--
//bbb.bbb.bbb The Internet node
- This specifies the node on the Internet where the file
is located.
If not included, it defaults to the computer on which the
browser is running, which is appropriate for
access method
file:
The node may optionally be followed by a colon and the port number.
Most browsers default to port 80, which is also what most
servers use to reply to the browser.
For access method ftp: the node name may take the form
//user[:password]@host.
Without a user name, the user anonymous is used.
/ccc/ccc/ccc The file path
- This is the pathname of the file to be retrieved, including the
directories, subdirectories, and filename.
A server can specify the "root" of the directory
system recognized by an access type as some subordinate directory.
This restricts access to files subordinate to that directory.
?ddd Arguments
- Depending upon the access method, and the file accessed,
characters can follow the file name, separated by some pre-defined
special character (e.g. "#", "?", "&", etc.).
This information can then be used by the access method as additional
arguments for the access. In the case of access method
http: where the file is an executable cgi-bin program
registered with the server, the arguments are passed to the program.
- Further References
-
http://www.w3.org/hypertext/WWW/Addressing/URL/5_BNF.html
- BNF Specification of URLs.
- Minimum Attributes
- The leading ampersand and trailing semi-colon are required.
These main four special characters are specifically included
in the Version 2 specification.
<
- < (less than sign)
-
>
- > (greater than sign)
-
&
- & (The ampersand sign itself)
-
"
- " (quote character)
- Variations
- The
" is specified as being either a single
or double quote, but most browsers render it as a double quote.
All the remaining special character entity names are listed in
http://www.sandia.gov/sci_compute/symbols.html
Not all of those special characters are recognized by all browsers.
The entity name of many of the proposed characters is case sensitive
and intentionally includes mixed case which must be entered
exactly as specified.
Since most browsers are insensitive to case for HTML names,
many browsers do not require the entity names of the main four special
characters to be lower case.
-
&#nn;
- ISO Latin-1 character number "nn"
(the number sign "#" is required)
The following document displays all the ISO Latin-1 characters
and can be used to see what they will produce on your browser.
http://www.sandia.gov/sci_compute/iso_symbol.html
The Version 2 Specification recommends referencing special characters
with the entity names described above instead of using these numeric
ISO Latin-1 code entity names.
- Minimum Attributes
- A standard set of icon names is expected to be
recognized by the browser for use by the DINGBAT attribute
in the H1, H2, H3, H4, H5, H6, and UL elements or as hypertext links
to an image.
The browser may either display them from local code/files, or
may expand them to URLs.
Similar to special characters, these names are case sensitive,
and are enclosed in the "
&" and
";" characters.
- Variations
- Standard icons are proposed in Version 3.
Browsers are likely to provide extensions to the standard set of icons.
The following document lists the currently proposed icon entity names:
http://www.sandia.gov/sci_compute/icons.html
This document is a merging of information from a variety
of other documents obtained from the WWW.
Everything in this document was copied or borrowed
from some other Web document, most of which are recognized
in the Acknowledgements below.
While there exist a number of Beginner's Guides
to writing HTML, verbal descriptions of parts of HTML, and
technical Document Type Definitions (DTD) specifications of the language,
I could not find a concise reference document for the language.
This reference document is an attempt to fill that gap.
While I have made every effort to be complete,
that is always an unattained goal,
especially since I am not involved in the development or
standardization of this language.
The information in this document is the best I have been able to find.
If I have something missing or wrong, please send me e-mail
with a definitive source so that I can keep this document
as current, accurate, and complete as possible.
The mention, or lack of mention, of any HTML browser product, service, or
company shall not be construed as either a positive or negative
endorsement of or comment about such product, service, or company.
At most it expresses my personal knowledge or ignorance of the information.
This document is neither intended to be nor capable of being an exhaustive
discussion of browser capabilities. It is focused on Sandia's internal needs.
Please also refer to the standard
Sandia disclaimer of liability.
Thanks to the following sources from which I have liberally borrowed.
http://www.w3.org/hypertext/WWW/MarkUp/MarkUp.html
- The general home page for HTML information at WWW.
http://www.w3.org/hypertext/WWW/MarkUp/html-spec/L2index.html
- This alphabetical listing of HTML elements for Version 2,
constructed by Dan Connolly, formed the original structure of this document.
Prior to Dan Connolly's move to
World Wide Web Consortium (W3C) at MIT, this reference was:
http://www.hal.com/users/connolly/html-spec/htmlindex.html
http://www.ucc.ie/~pflynn/books/htmlcard.html
- A quick reference card to the HTML elements, organized by logical function.
This card appears in printed form in Spinning the Web (1-850-32141-8)
by Andrew Ford, and The WorldWideWeb Handbook (1-850-32205-8)
by Peter Flynn, both published by International Thomson Computer Press.
http://lcweb.loc.gov/global/html.html
- The Library of Congress index of links about HTML.
http://www.utirc.utoronto.ca/HTMLdocs/NewHTML/htmlindex.html
- A draft of the upcoming book on HTML Documentation by Ian Grahm.
http://www.ncsa.uiuc.edu/SDG/Software/Mosaic/Docs/fill-out-forms/overview.html
- Documentation of Mosiac for X version 2.0 fill-out form support.
http://www.ncsa.uiuc.edu/General/Internet/WWW/HTMLPrimer.html
- The HTML Primer developed by NCAR.
http://www.w3.org/hypertext/WWW/MarkUp/HTML.html
- The draft 1.2 of Internet MIME Content Type (RFC 1341)
which expired 13 Jan 1994.
It is a description of Version 1 HTML
written by Tim Berners-Lee and Daniel Connolly.
http://kuhttp.cc.ukans.edu/lynx_help/HTML_quick.html
- A quick reference to HTML Version 1 by Michael Grobe.
http://www.w3.org/hypertext/WWW/MarkUp/html-spec/html.dtd
- The Document Type Definition (DTD) of the Version 2 specification for HTML.
Prior to Dan Connolly's move to
World Wide Web Consortium (W3C) at MIT, this reference was:
http://www.hal.com/users/connolly/html-spec/html-pubtext.html
http://www.ics.uci.edu/pub/ietf/html/html2/index.html
- HTML Version 2 as of 29 Nov 1994 as an Internet Media Type (RFC 1590)
and MIME Content Type (RFC 1521)
written by Tim Berners-Lee and Daniel Connolly.
http://www.w3.org/hypertext/WWW/MarkUp/Text.html
- The syntax of the text of HTML.
http://home.mcom.com/home/services_docs/html-extensions.html
- The description of the extensions to HTML used by Netscape, Version 1.0.
http://www.netscape.com/assist/net_sites/html_extensions.html
- The description of the extensions to HTML used by Netscape, Version 1.1.
http://hoohoo.ncsa.uiuc.edu/cgi/overview.html
- This document appears to be a definitive reference to the
Common Gateway Interface, which describes the structure of cgi-bin programs.
These programs are required for the ISMAP attribute of the IMG element,
as well as for processing FORM element input.
http://hoohoo.ncsa.uiuc.edu/docs/setup/admin/Imagemap.html
- This document discusses, with examples,
how the NCSA image map utility works.
This is a cgi-bin program that is useful with the
ISMAP attribute on the IMG element.
http://hoohoo.ncsa.uiuc.edu/docs/setup/admin/NewImagemap.html
- This document discusses, with examples,
how the newer version of the NCSA image map utility works.
This is a cgi-bin program that is useful with the
ISMAP attribute on the IMG element.
This newer imagemap program is much more versatile
than the original version distributed with the NCSA HTTP1.3 server.
The document describes the advantages of the new program,
and provides directions to the source code.
http://www.w3.org/hypertext/WWW/MarkUp/HTMLPlus/htmlplus_1.html
- HTML+ (a superset of Version 2, and the precursor to Version 3)
as of 8 Nov 1993, by David Raggett. Includes some interesting possibilities.
http://www.w3.org/hypertext/WWW/Arena/tour/start.html
- An overview of the proposed features of Version 3, and identification
of those proposals likely to be deferred until Version 3.1.
Also identifies access to a test browser designed to display the new
Version 3.0 features as part of the review process.
http://www.hpl.hp.co.uk/people/dsr/html/CoverPage.html
- A current draft of the text for a proposed Version 3 as an Internet RFC
by David Raggett. This link is identical to
http://www.hpl.hp.co.uk/people/dsr/html3/CoverPage.html
http://ppewww.ph.gla.ac.uk/~flavell/iso8859/iso8859-1.html
- An excellent analysis of the relationship of the ISO8859 Latin-1
character set with HTML entities, including representational tables.
http://www.willamette.edu/html-composition/strict-html.html
- This is my personal favorite of the many documents describing
how to write good HTML, including "Common Errors" and
"Things to Avoid".
http://www.w3.org/hypertext/WWW/Provider/Style/Overview.html
- The Style Guide at the World Wide Web Consortium (W3C) at MIT,
written by Tim Berners-Lee.
Last Modified: 8 September 1995
Statistics on http://www.sandia.gov/sci_compute/html_ref.html
From Mar 21, 1995 through
Oct 10, 1995,
this document has been accessed from
different sites outside Sandia.
Michael J. Hannah
Sandia National Laboratories
mjhanna@sandia.gov
Welcome to Sandia National Labs
||
DOE Home Page
||
Doing Business with Sandia
||
Search Sandia Information
||
Send questions about Sandia
||Sandia disclaimer of liability