The new elements in HTML 4.0 are: ABBR, ACRONYM, BDO, BUTTON, COLGROUP, DEL, FIELDSET, FRAME, FRAMESET, IFRAME, INS, LABEL, LEGEND, NOFRAMES, NOSCRIPT, OBJECT, OPTGROUP, PARAM, SPAN, TBODY, TFOOT, THEAD, and Q.
The following elements are deprecated: APPLET, BASEFONT, CENTER, DIR, FONT, ISINDEX, MENU, S, STRIKE, and U.
The following elements are obsolete: LISTING, PLAINTEXT, and XMP. For all of them, authors should use the PRE element instead.
HTML 4.0 features many changes to promote accessibility, including:
Authors may now specify profiles that provide explanations about meta specified with the META or LINK elements.
The HTML 4.0 table model has grown out of early work on HTML+ and the initial draft of HTML3.0. The earlier model has been extended in response to requests from information providers as follows:
The HTML 4.0 table model also satisfies requests for optional column-based defaults for alignment properties, more flexibility in specifying table frames and rules, and the ability to align on designated characters. It is expected, however, that style sheets will take over the task of rendering tables in the near future.
In addition, a major goal has been to provide backwards compatibility with the widely deployed Netscape implementation of tables. Another goal has been to simplify importing tables conforming to the SGML CALS model. The latest draft makes the align attribute compatible with the latest versions of the most popular browsers. Some clarifications have been made to the role of the dir attribute and recommended behavior when absolute and relative column widths are mixed.
A new element, COLGROUP, has been introduced to allow sets of columns to be grouped with different width and alignment properties specified by one or more COL elements. The semantics of COLGROUP have been clarified over previous drafts, and rules="basic" replaced by rules="groups".
The style attribute is included as a means for extending the properties associated with edges and interiors of groups of cells. For instance, the line style: dotted, double, thin/thick etc; the color/pattern fill for the interior; cell margins and font information. This will be the subject for a companion specification on style sheets.
The frame and rules attributes have been modified to avoid SGML name clashes with each other, and to avoid clashes with the align and valign attributes. These changes were additionally motivated by the desire to avoid future problems if this specification is extended to allow frame and rules attributes with other table elements.
This specification introduces several new attributes and elements that affect forms:
HTML 4.0 supports a larger set of media descriptors so that authors may write device-sensitive style sheets.
HTML 4.0 supports frame documents and inline frames.
Many elements now feature event attributes that may be coupled with scripts; the script is executed when the event occurs (e.g., when a document is loaded, when the mouse is clicked, etc.).
HTML 4.0 integrates the recommendations of [RFC2070] for the internationalization of HTML.
However, this specification and [RFC2070] differ as follows: