(James Pickering -- 2002.05.06 comp.infosystems.www.authoring.html)
I was asked, via private e-mail, why I am currently using ISO-HTML for Web page creation. I thought it appropriate to repeat my reply in this Forum:
I actually change the markup "flavor" for many of my pages from time to time -- I am a Technical Advisor (volunteer) for a group of severely disabled (deafblind and respirator dependent Duchenne Muscular Dystrophy) Web authors and I find it is easier to provide markup exemplars using my own pages than constructing special templates. I am a proponent of the International Standard represented by ISO-HTML (ISO/IEC 15445:2000) for our purposes, although its rigidity can render it unsuitable for Web pages that emphasize presentation over content or, in some cases, those that employ tables for layout. Because of its "strictness", ISO-HTML markup produces pages that can be easily modified to Validate as W3C HTML 4.01 (strict), XHTML Basic, XHTML 1.0 (strict) or XHTML 1.1. All that is needed is to substitute the appropriate DOCTYPE Declaration and, in the case of XHTML versions, adjust the empty element tags -- I write all of my markup in lowercase as a matter of course. Dave Raggett's excellent utility "Tidy" is a valuable resource here.
Here is my assessment of the salient features of ISO-HTML .....
1. It is a more rigorous ("stricter") implementation of W3C (World Wide Web Consortium) HTML 4.01 (Strict).
For instance, the hierarchy of the header element .......
H1 ..... Major section header H2 ..... Section header H3 ..... Subsection header H4 ..... Subsubsection header H5 ..... Subsubsubsection header H6 ..... Minor subsubsubsection header
....... is rigidly enforced. For example, H4 is not allowed to precede H3 at any place in a document.
2. Numerous W3C HTML 4.01 elements are refined in ISO-HTML.
3. Numerous W3C HTML 4.01 attributes are omitted from the standard or their use is restricted.
To quote from the Users Guide .......
"The W3C Recommendation for HTML 4.01 provides a number of attributes that are not supported by the International Standard. They have been omitted because they are used to describe appearance rather than structure, or because the feature is considered to be still too unstable or immature for an International Standard:"
..... those that are omitted altogether are .......
ALIGN ALINK BGCOLOR BORDER CHAR CHAROFF COMPACT HEIGHT HSPACE ONBLUR ONCHANGE ONCLICK ONDBLCLICK ONFOCUS ONKEYDOWN ONKEYPRESS ONKEYUP ONLOAD ONMOUSEDOWN ONMOUSEMOVE ONMOUSEOUT ONMOUSEOVER ONMOUSEUP ONRESET ONSELECT ONSUBMIT ONUNLOAD STYLE TARGET VALIGN VLINK VSPACE WIDTH
....... those omitted for specific elements are .......
ALT ..... omitted from INPUT ARCHIVE ..... omitted from OBJECT BACKGROUND ..... omitted from BODY CELLPADDING ..... omitted from TABLE CELLSPACING ..... omitted from TABLE CLEAR ..... omitted from BR COORDS ..... omitted from A FRAME ..... omitted from TABLE LINK ..... omitted from BODY NAME ..... omitted from FORM NAME ..... omitted from IMG NOSHADE ..... omitted from HR NOWRAP ..... omitted from TD and TH RULES ..... omitted from TABLE SHAPE ..... omitted from A SIZE ..... omitted from HR SRC ..... omitted from INPUT START ..... omitted from OL TEXT ..... omitted from BODY TYPE ..... omitted from LI, OL and UL USEMAP ..... omitted from INPUT VALUE ..... omitted from LI VERSION ..... omitted from HTML
Note in passing ....... HEIGHT and WIDTH parameters for IMG are designated in style sheets (which must be linked -- embedded style constructs are not allowed).
CAVEAT: The above list is my own compilation -- I do not guarantee its completeness -- check the Users Guide for verification.
4. The ISO standard clearly separates content from presentation as delineated in the following quote from the Users Guide .......
"The International Standard is based on the well established principle that it is good document design to separate the content of a document from the intended style in which it is to be presented to a reader ..... "
5. Finally, the methodology for accomplishing presentation is outlined in the following quote from the Users Guide .......
"Although the International Standard does not specify a style sheet language, this User's Guide recommends that authors of ISO-HTML documents use Cascading Style Sheets as specified by the World Wide Web Consortium."
1) The User's Guide to ISO/IEC 15445:2000 (ISO-HTML) is at -- http://www.cs.tcd.ie/15445/UG.html
2) The three HTML Validators that I use support ISO-HTML .....
a) W3C Validation Service -- http://validator.w3.org/
b) WDG Validator (by Liam Quinn) -- http://www.htmlhelp.com/tools/validator/
c) Page Valet Validator (an element of the Site Valet service of Nick Kew) -- http://valet.webthing.com/page/
Pickering Pages http://www.jp29.org/ Validated ISO-HTML/CSS/RDF
Omitting height and width attributes from images considered bad.
These properties are directly related to the individual image, so assigning these from a (external-) stylesheet is only possible by assigning a ID to each image (or class incase of more than one image with the same width/height).
In this case you essentially have separated information about one element, to two different places: the image (defined by its source attribute) in the html source and the other properties in the stylesheet.
Anyway, I would end up never specifying a width- and height attribute for my images if this would be enforded.