The idea of the BANNER elements was to use a fixed block before the block text, which had in the HTML 3.0 Draft a special element. CSS2 brought back the functionality of this element.

SPOT is an unnecessary element to set the id attribute.

The cite and datetime are informative attributes. They give information explaining why and when a document was changed or (concerning Q and BLOCLQUOTE elements) where some fragment has been borrowed. They can show in Opera and Mozilla Gecko browsers by using special CSS, for example ins:before {content:attr(cite);}. Ordinary CSS can be applied and they have default presentation in some browsers. These elements and the attribute cite, which can be used also with elements BLOCKQUOTE and Q could allow dynamic content without using CGI-encoding. The functionality of these elements can be reached server or author side scripting languages, which is not user friendly to average web authors. -->

It is supported in MS IE 2.0+. MARQUEE can be replaced with JavaScript of Java-applets.

In addition this group includes the BLOCKQUOTE element. In the Modularization of XHTML they belong directly to the Text Module. Transitional attributes (for example width) need in XHTML 1.1 the Legacy Module. H1-H6 has been classified before the Modularization of XHTML only as heading elements, but now they a sub-class of block phrasal elements.

Use normally DIV or P elements to create ordinary blocks.

BLOCKQUOTE is a Block Phrasal and Q is an Inline Phrasal element, which belong in the Modularization of XHTML directly to the Text Module. I explain the usage of the cite attribute when I handle INS and DEL elements.

Opera 4.0+ and Mozilla Gecko browsers (for example Netscape 6.0+) support special quotations marks with the CSS implementation by using the content property.

Some authors (mis)use BLOCKQUOTE as presentational purposes using nested BLOCKQUOTE elements. Today it is desirable to use CSS and define margin and padding properties instead nested elements. Only in presentational purposes, use instead the DIV element.

DIV and P belong directly in the Modularization of XHTML to the Text Module. DIV can be used also into presentational purposes.

CENTER can be understood both as a structural and presentational element. Because CENTER is used primary into presentational purposes and it is in practise a shortcut of DIV class="c", it belongs to the Legacy Module. The transitional attributes align to DIV and P belongs also to the same module. CENTER and can be replaced with other elements or CSS like also the transitional attribute. If the author wants to use them, he should add the Legacy Module to the XHTML Basic DTD.

In XHTML all non-empty elements needs termination tags. I recommend to put end-tags to all elements, which can have them even if it is not necessary in HTML.

Block-level elements have different margins around them. For example P creates an empty line between each elements. DIV and CENTER don't create any margin (the author can add it with CSS). They just create a line break before and after them.

The fact, that Opera 4.x supports align, height and width to most block level elements and some form elements might be a side-effect to keep the size of the browser small, because less conditions => smaller code!. All transitional attributes can be replaced in principle with CSS (Opera 2.1 supports the attribute clear, but the corresponding property clear is not widely supported; I don't have tested if newest Opera browsers support it anymore).

In the Modularization of XHTML it belongs to the Presentation Module. If this module is selected it is added to the Text Module. Transitional attributes (noshade etc.) need the additional Legacy Module in XHTML 1.1. It has no effect in newest Opera browsers.

That's why they don't belong to the List Module of the Modularization of XHTML. I recommend to use instead of them other list elements.

Transitional attributes (type etc.) need in XHTML 1.1 the Legacy Module.

The attribute compact doesn't work in many browsers. The corresponding CSS works only in Opera 4.+ and newest Opera browsers don't support the compact attribute.
With CSS can create nice markers, but Netscape 4.x doesn't support them.

If the margin or padding CSS-properties are defined to the element LI, it is remarkable that default setting are counted differently in Netscape 6.x as Opera and MS IE.

Transitional attributes (bgcolor etc.) need in XHTML 1.1 the Legacy Module.

According to the DTD, TBODY is required in HTML 4.0 tables. This is not however absolute necessary. If there is no THEAD or TFOOT and only one TBODY is needed, TBODY can be omitted and TR can be a direct required child-element.

Tables have the simple table model (in the Modularization of XHTML it is called as the Basic Tables Module), which is supported by Netscape 1.1+, MS IE 2.0+ and Opera 2.1+ browsers.

TBODY etc. belongs to the complex table model (in the Modularization of XHTML it is called as the Tables Module), which is supported by MS IE 3.x+, Mozilla Gecko and partially in Opera 4.x-6.x browsers. Opera Software promise to support in those browsers only the TFOOT element in the complex table model. Indeed the functionality of THEAD and TFOOT don't work as intended in printing. Opera and MS IE don't print THEAD and TFOOT to every page in large tables. Mozilla 0.7 printed THEAD to every page, but it didn't print TFOOT at all. I have not checked if Opera 7.x supports all of them properly.

The CSS2 Table model works partially also in Mozilla Gecko and buggy in Opera 4.x-6.x browsers. I have not checked if Opera 7.x supports it properly.

If you want define with CSS 1 pixel borders or no borders to table cells to Netscape 4.x, you need to add border="0" and cellspacing="0" attributes. Also some other browsers need them. MS IE 5.x+ and Opera 4.x+ don't need them.
The attribute summary is for future aural browsers. HTML Tidy ask to add it for this purpose.

Normal tables are slow, if they are long, because the browser needs to read the whole information of the table before it can render it. CSS2 gives the possibility to use alternatively the fast table layout (table-layout:fixed). The main table and note tables use it.

The transitional attribute align needs in XHTML 1.1 the Legacy Module.

Caption side can be defined also with CSS, but it is not widely supported. The CAPTION element doesn't work in Opera 4.-6.x properly, if THEAD is used (this matter has been fixed in Opera 7.x). CSS to this element doesn't work according to the specifications in MS IE browsers.

Few browsers don't support tables. Blooberry proposes to add <BR> after the CAPTION and table row content. If you put <BR> before </TD>, </TH> or </CAPTION>, it is ok.

They are supported by MS IE 4.x+ except that attributes char and charoff are not supported. Opera Software informs that all table-related attributes are supported in Opera 7.x except char and charoff for table cells.

W3C advice at this way in the XHTML 1.0 transitional DTD:

Use thead to duplicate headers when breaking table across page boundaries, or for static headers when tbody sections are rendered in scrolling panel.

Use tfoot to duplicate footers when breaking table across page boundaries, or for static footers when tbody sections are rendered in scrolling panel.

Use multiple tbody sections when rules are needed between groups of table rows.

Static headers or footers can be created with CSS (position:fixed; I handle this matters in my CSS site).

Transitional attributes (bgcolor etc.) need in XHTML 1.1 the Legacy module.

Attributes abbr, axis, char, charoff, headers and scope to TD/TH are not supported in any browser. Proprietary attributes can be replaced with CSS. Opera Software informs that all table-related attributes are supported in Opera 7.x except char and charoff for table cells.

LAYER can be replaced in Mozilla Gecko browsers with CSS (position:fixed can create layered fixed navigation elements). Mozilla Gecko browsers support IFRAME, which can replace ILAYER. Indeed by using LAYER with NOLAYER to give the alternative content to other browsers, the LAYER element is only harmful in validating the document.

The 4.x series support proprietary DHTML, but Mozilla Gecko based browsers will not support any proprietary DHTML. DHTML scripts should be made for Netscape 6.x+ and other Gecko browsers by using methods getDocumentElement() or document.getElementById("id_name") (they are explained in the ECMAScript language binding of the DOM (Document Object Model) level 1 specification. According to an e-mail these methods work also in MS IE 5.0 and Opera Software has been added experimental support of DOM into Opera 4.x+ browsers. It works relative well starting from Opera 5.x but Opera 7.x give really wide support for DOM. It is then in principle possible to use the same DHTML in MS IE, Netscape and Opera browsers.

Indeed Mozilla Gecko browsers have default definition to it in the /res/html.css -file, when they can at least identify the element. I tested it in Mozilla 0.7 and the functionality of the element didn't work and CSS worked partially and buggy. Even if Mozilla 0.7 at some level identifies it, it doesn't really support it. It is more reasonable to use instead TABLE or DIV elements.

According to the documentation of Netscape attributes of MULTICOL can be used also to the element DIV.