HTML modes
About HTML
Most of the documents ("pages") found on the World Wide Web are written
in HTML (HyperText Markup Language). HTML was originally designed
as a standard
hard- and software independent way of formatting documents. It is an
application of SGML (Standard Generalized Markup Language).
The only official standard is HTML 2.0, which contains very limited
possibilities. The W3 consortium was
developing a new, extended standard, HTML 3.0.
Meanwhile, in the recent boom of Internet and the World Wide Web, some browser
manufacturers have introduced several ad-hoc extensions to HTML, of which
many didn't fit in the new HTML 3.0 standard. Probably because this would make
HTML 3.0 an academic standard without any practical use, the development of
HTML 3.0 was abandoned. AWeb supports some of the extensions found in HTML 3.0.
Recently the W3 group proposed a new HTML 3.2 standard, which contains many
of the widely used NetScape ® and Microsoft ® Internet Explorer specific
extensions. AWeb will fully support HTML 3.2 in the near future.
The large browser manufacturers have introduced other tags, which aren't
included in the HTML 3.2 standard. AWeb will try to support most of these
non-standard extensions.
To make things even more inconvenient, some earlier versions of popular PC
browsers didn't stick to the SGML rules. And even recent versions of
those browsers still have problems with SGML comments. Because many
people design their pages using these browsers, there are many documents
on the web that just are bad HTML.
HTML modes
AWeb does its best to display all pages correctly, but sometimes you have
to set the way HTML should be interpreted to get the best results.
You can choose out of three HTML modes:
- Strict
- In strict HTML mode, AWeb understands only the proposed
HTML 3.2 standard.
- Tolerant
- In tolerant HTML mode, AWeb also understands other extensions.
These are both extensions specific to other browsers, and HTML 3.0
extensions that can't be found in HTML 3.2.
A list of all extensions that AWeb
supports is given below.
- Compatible
- In compatible HTML mode (a nice way of formulating "buggy"),
AWeb tries to interpret buggy HTML.
A description of compatibility-mode deviations
to the standards is given below.
Set one of these in the settings page.
AWeb currently supports the following proposed and/or other extensions to the
HTML 2.0 standard. With each extension, the HTML modes that recognize
the extension are mentioned within parentheses.
- <BODY BACKGROUND=url BGCOLOR=#rrggbb TEXT=#rrggbb
LINK=#rrggbb VLINK=#rrggbb ALINK=#rrggbb>
- Background images and document colours.
If no BACKGROUND or BGCOLOR is given, then TEXT, LINK, VLINK and ALINK are ignored.
(strict, tolerant, compatible)
- <DIV ALIGN=align>
- <Hn ALIGN=align>
- <P ALIGN=align>
- <CENTER>
- Alignment of divisions, headings and paragraphs. align =
LEFT, CENTER and RIGHT are supported.
(strict, tolerant, compatible)
- <DFN>
- <STRIKE>
- Phrase markup.
(strict, tolerant, compatible)
- <IMAGE BORDER=n WIDTH=n HEIGHT=n>
- Image border size and preset dimensions.
(strict, tolerant, compatible)
- <HR ALIGN=align NOSHADE SIZE=n WIDTH=n%|n>
- Enhanced horizontal ruler.
(strict, tolerant, compatible)
- <OL START=n TYPE=otype>
- <UL TYPE=utype>
- <LI TYPE=otype|utype VALUE=n>
- Enhanced lists. otype can be A, a,
I, i or 1. utype can be
DISC, CIRCLE or SQUARE.
(strict, tolerant, compatible)
- <OL CONTINUE SEQNUM=n>
- <UL PLAIN SRC=url DINGBAT=name>
- <LI SKIP=n SRC=url DINGBAT=name>
- List extensions from the HTML 3.0 specification.
(tolerant, compatible)
- &icon.name;
- All proposed WWW
icon entities (dingbats)
(tolerant, compatible)
- <FRAME SRC=url NAME=name>
- Very limited frame support. AWeb does not yet support frames, but
it recognizes the <FRAME> tag and shows a hyperlink for each
document. You will still see those annoying "your browser doesn't
support frames, download NetScape here" messages, but at least you
can access the information.
(tolerant, compatible)
As mentioned above, some pages contain bad HTML. When you view such a
page, it can look distorted. You can expect large parts of the page missing,
links to URLs that seem to contain HTML tags, and other strange things.
If you encounter such problems, try using the compatible HTML
mode of AWeb. Warning: Using compatible HTML mode,
documents containing valid HTML might look distorted in turn.
In compatible mode, AWeb exposes the following deviations from the
SGML standard:
- quoted attribute values are terminated by any occurrence of ">"
- quoted attributes that contain URLs, like HREF, SRC and ACTION, are
terminated by whitespace
- comments are terminated by any occurrence of "-->"
Back to the AWeb Home Page.