HTML Comparison Table

  Element / Attribute IEx NS Mos Spec.

<A> 1.0
  ACCESSKEY 4.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  HREF 2.0
  INDEXSTRING NS 4.0
  METHODS 2.0
  NAME 2.0
  REL 2.0
  REV 2.0
  TARGET 4.0
  TOCSTRING NS 4.0
  URN 2.0
<ACRONYM> 4.0
<ADDRESS> 2.0
<APPLET> 3.2
  ALIGN 3.2/NS 2.0
  ALT 3.2/NS 2.0
  ARCHIVE 3.2/NS 3.0
  CODE 3.2/NS 2.0
  CODEBASE 3.2/NS 2.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  HEIGHT 3.2/NS 2.0
  HSPACE 3.2/NS 2.0
  MAYSCRIPT NS 3.0
  NAME 3.2/NS 2.0
  SRC 3.2/NS 2.0
  WIDTH 3.2/NS 2.0
<AREA> 3.2
  ALT 3.2/IEx 2.0
  COORDS 3.2/IEx 2.0
  HREF 3.2/IEx 2.0
  NAME 3.2/IEx 2.0
  SHAPE 3.2/IEx 2.0
  TARGET 3.2/IEx 2.0
<B> 3.2
<BASE> 3.2
  HREF 2.0
  TARGET 2.0/NS 2.0
<BASEFONT> 4.0
  COLOR 4.0
  FACE 4.0/IEx 2.0
  SIZE 4.0
<BGSOUND> IEx 2.0
  BALANCE IEx 4.0
  LOOP IEx 2.0
  SRC IEx 2.0
  VOLUME IEx 2.0
<BIG> 3.2
<BLOCKQUOTE> 2.0
<BODY> 2.0
  ALINK 3.2
  BACKGROUND 3.2
  BGCOLOR 3.2
  BGPROPERTIES IEx 2.0
  BOTTOMMARGIN IEx 4.0
  LEFTMARGIN IEx 4.0
  LINK 3.2
  RIGHTMARGIN IEx 4.0
  SCROLL IEx 4.0
  TEXT 3.2
  TOPMARGIN IEx 4.0
  VLINK 3.2
<BR> 2.0
  CLEAR 3.2
<BUTTON> 4.0
  ACCESSKEY 4.0
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  DISABLED 4.0
  TYPE 4.0
<CAPTION> 3.2
  ALIGN 3.2
  VALIGN 4.0/IEx 2.0
<BIG> 3.2
<CITE> 2.0
<CODE> 2.0
<COL> 4.0
  ALIGN 4.0
  VALIGN 4.0
<COLGROUP> 4.0
  ALIGN 4.0
  SPAN 4.0
  VALIGN 4.0
  WIDTH 4.0
<COMMENT> 4.0
<DD> 2.0
<DEL> 4.0
  CITE 4.0
  DATETIME 4.0
<DFN> 3.2
<DIR> 2.0
<DIV> 3.2
  ALIGN 3.2
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  COMPACT 3.2
<DT> 2.0
<EM> 2.0
<EMBED> 3.2
  ALIGN 3.2
  ALT 3.2
  BORDER 3.2
  HIDDEN 3.2
  HSPACE 3.2
  NAME 3.2
  PALETTE 3.2
  PLUGINSPACE 3.2
  VSPACE 3.2
<FIELDSET> 4.0
<FONT> 3.2
  COLOR 3.2
  FACE 3.2
  POINT-SIZE NS 4.0
  SIZE 3.2
  WEIGHT NS 4.0
<FORM> 2.0
  ACTION 2.0
  ENCTYPE 2.0
  METHOD 2.0
  NAME 2.0
  TARGET 3.2
<FRAME> 4.0
  BORDERCOLOR 4.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  FRAMEBORDER 4.0
  FRAMESPACING 4.0
  MARGINHEIGHT 4.0
  MARGINWIDTH 4.0
  NORESIZE 4.0
  SCROLLING 4.0
  SRC 4.0
<FRAMESET> 4.0
  BORDER 4.0
  BORDERCOLOR 4.0
  COLS 4.0
  FRAMEBORDER 4.0
  FRAMESPACING 4.0
  ROWS 4.0
<HR> 2.0
  ALIGN 3.2
  COLOR 3.2
  NOSHADE 3.2
  SIZE 3.2
  WIDTH 3.2
<Hx> 2.0
  ALIGN 3.2
<I> 2.0
<IFRAME> 4.0
  ALIGN 4.0
  BORDER 4.0
  BORDERCOLOR 4.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  FRAMEBORDER 4.0
  HEIGHT 4.0
  HSPACE 4.0
  NAME 4.0
  SCROLLING 4.0
  SRC 4.0
  VSPACE 4.0
  WIDTH 4.0
<ILAYER> NS 4.0
  ABOVE NS 4.0
  BACKGROUND NS 4.0
  BELOW NS 4.0
  BGCOLOR NS 4.0
  LEFT NS 4.0
  NAME NS 4.0
  SRC NS 4.0
  TOP NS 4.0
  VISIBILITY NS 4.0
  WIDTH NS 4.0
  Z-INDEX NS 4.0
<IMG> 2.0
  ALIGN 2.0
  ALT 2.0
  BORDER 2.0
  CONTROLS IEx 2.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  DYNSRC IEx 2.0
  HEIGHT 2.0
  HSPACE 3.2
  ISMAP 2.0
  LOOP IEx 2.0
  LOOPDELAY IEx 2.0
  LOWSRC 3.2
  NAME 3.2
  SRC 2.0
  START IEx 2.0
  USEMAP 3.2
  VRML IEx 3.0
  VSPACE 3.2
  WIDTH 2.0
<INPUT> 2.0
  ACCESSKEY 4.0
  ALIGN 2.0
  CHECKED 2.0
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  DISABLED 4.0
  MAXLENGTH 2.0
  NAME 2.0
  READONLY 4.0
  SIZE 2.0
  SRC 2.0
  TABINDEX 4.0
  TYPE 2.0
  VALUE 2.0
<INS> 4.0
  CITE 4.0
  DATETIME 4.0
<ISINDEX> 2.0
  ACTION 2.0
  PROMPT 2.0
<KBD> 2.0
<KEYGEN> NS 3.0
  CHALLENGE NS 3.0
  NAME NS 3.0
<INPUT> 4.0
  ACCESSKEY 4.0
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  FOR 4.0
<LAYER> NS 4.0
  ABOVE NS 4.0
  BACKGROUND NS 4.0
  BELOW NS 4.0
  BGCOLOR NS 4.0
  CLIP NS 4.0
  LEFT NS 4.0
  NAME NS 4.0
  SRC NS 4.0
  TOP NS 4.0
  VISIBILITY NS 4.0
  WIDTH NS 4.0
  Z-INDEX NS 4.0
<LEGEND> 4.0
  ALIGN 4.0
<LI> 2.0
  TYPE 4.0
<LINK> 2.0
  DISABLED 2.0
  HREF 2.0
  REL 2.0
  REV 2.0
  TYPE 2.0
<LISTING> 2.0
<MAP> 3.2
  NAME 3.2
<MARQUEE> IEx 2.0
  ALIGN IEx 2.0
  BEHAVIOR IEx 2.0
  BGCOLOR IEx 2.0
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  DIRECTION IEx 2.0
  HEIGHT IEx 2.0
  HSPACE IEx 2.0
  LOOP IEx 2.0
  SCROLLAMOUNT IEx 2.0
  SCROLLDELAY IEx 2.0
  TRUESPEED IEx 4.0
  VSPACE IEx 2.0
  WIDTH IEx 2.0
<MENU> 2.0
<META> 2.0
  CONTENT 2.0
  HTTP-EQUIV 2.0
  NAME 2.0
<MULTICOL> NS 3.0
  COLS NS 3.0
  GUTTER NS 3.0
  WIDTH NS 3.0
<OBJECT> 4.0
  ACCESSKEY 4.0
  ALIGN 3.2
  BORDER 4.0
  CLASSID 4.0
  CODE 4.0
  CODEBASE 4.0
  DATA 4.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  HEIGHT 4.0
  HSPACE 4.0
  NAME 4.0
  TABINDEX 4.0
  TYPE 4.0
  VSPACE 4.0
  WIDTH 4.0
<OL> 2.0
  START 3.2
  TYPE 3.2
<OPTION> 2.0
  NAME 3.2
  SELECTED 2.0
  TYPE 3.2
  VALUE 2.0
<P> 2.0
  ALIGN 3.2
<PARAM> 3.2
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  NAME 3.2
  VALUE 3.2
<PLAINTEXT> 2.0
<PRE> 2.0
  WIDTH 2.0
<Q> 4.0
  CITE 4.0
<S> 2.0
<SAMP> 2.0
<SELECT> 2.0
  ACCESSKEY 4.0
  ALIGN 2.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  DISABLED 4.0
  MULTIPLE 2.0
  NAME 2.0
  SIZE 2.0
  TABINDEX 4.0
  TYPE 4.0
<SMALL> 3.2
<SOUND> Mos 3.0
  DELAY Mos 3.0
  LOOP Mos 3.0
  SRC Mos 3.0
<SPACER> NS 3.0
  ALIGN NS 3.0
  HEIGHT NS 3.0
  SIZE NS 3.0
  TYPE NS 3.0
  WIDTH NS 3.0
<SPAN> 3.2
  DATAFLD IEx 4.0
  DATAFORMATAS IEx 4.0
  DATASRC IEx 4.0
  DIR 3.2
<STRIKE> 2.0
<STRONG> 2.0
<STYLE> 3.2
  DISABLED 4.0
  MEDIA 4.0
  TYPE 3.2
<SUB> 2.0
<SUP> 2.0
<TABLE> 3.2
  ALIGN 3.2
  BACKGROUND IEx 3.0
  BGCOLOR IEx 3.0
  BORDER 3.2
  BORDERCOLOR IEx 3.0
  BORDERCOLORDARK IEx 3.0
  BORDERCOLORLIGHT IEx 3.0
  CELLPADDING 3.2
  CELLSPACING 3.2
  COLS 4.0
  DATAFLD IEx 4.0
  DATAPAGESIZE IEx 4.0
  DATASRC IEx 4.0
  FRAME 3.2
  HEIGHT 3.2
  RULES 3.2
  VALIGN 4.0
  WIDTH 3.2
<TBODY> 3.2
  ALIGN 4.0
  BGCOLOR IEx 4.0
  VALIGN 4.0
<TD> 3.2
  ALIGN 3.2
  BACKGROUND IEx 3.0
  BGCOLOR IEx 3.0
  BORDERCOLOR IEx 3.0
  BORDERCOLORDARK IEx 3.0
  BORDERCOLORLIGHT IEx 3.0
  COLSPAN 3.2
  HEIGHT 3.2
  NOWRAP 3.2
  ROWSPAN 3.2
  VALIGN 3.2
  WIDTH 3.2
<TEXTAREA> 2.0
  ACCESSKEY 4.0
  ALIGN 2.0
  COLS 2.0
  DATAFLD IEx 4.0
  DATASRC IEx 4.0
  DISABLED IEx 4.0
  NAME 2.0
  READONLY 4.0
  ROWS 2.0
  TABINDEX 4.0
  WRAP 3.2
<TFOOT> 3.2
  ALIGN 4.0
  BGCOLOR IEx 4.0
  VALIGN 4.0
<TH> 3.2
  ALIGN 3.2
  BACKGROUND IEx 3.0
  BGCOLOR IEx 3.0
  BORDERCOLOR IEx 3.0
  BORDERCOLORDARK IEx 3.0
  BORDERCOLORLIGHT IEx 3.0
  COLSPAN 3.2
  HEIGHT 3.2
  NOWRAP 3.2
  ROWSPAN 3.2
  VALIGN 3.2
  WIDTH 3.2
<THEAD> 3.2
  ALIGN 4.0
  BGCOLOR IEx 4.0
  VALIGN 4.0
<TR> 3.2
  ALIGN 3.2
  BGCOLOR 3.2
  BORDERCOLOR IEx 3.0
  BORDERCOLORDARK IEx 3.0
  BORDERCOLORLIGHT IEx 3.0
  VALIGN 3.2
<TT> 2.0
<U> 2.0
<UL> 2.0
  TYPE 3.2
<VAR> 2.0
<XMP> 2.0


NOTE :
All elements that can be used within the <BODY> of a HTML document can take the CLASS, ID, LANG, LANGUAGE, STYLE and TITLE attributes as well as those listed below. They have not been added for reasons of brevity and clarity. Their browser suppport is as follows:

CLASS Y
from v3.0
Y
from v4.0
4.0
ID Y
from v3.0
Y
from v4.0
4.0
LANG Y
from v4.0
4.0
LANGUAGE Y
from v4.0
4.0
STYLE Y
from v3.0
Y
from v4.0
4.0
TITLE Y
from v4.0
4.0

NOTE : The browsers compared for this table were:
Internet Explorer :Windows 95/NT(4) version 4.0
Netscape :Windows 95/NT(4) version 4.03
Mosaic :Windows 95 version 3.0
A note about the 'Specification' column
For this column, I have tried to detail either which specification covers the element, or which version of which browser introduced the element or attribute. This required trailing through release documentation provided by the respective browser vendors, which up until recently has not been of the highest quality (in terms of completeness). Some entries may be wrong.
Where an element/attribute that was introduced by a browser and subsequently added to a HTML specification, only the specification is given.
HTML 4.0 is currently still in it's draft specification stages, although is reaching stability, so has been quoted as 'HTML 4.0' instead of Cougar (it's original code name). The browser name abbreviations are as follows :
NS : Netscape
IEx : Internet Explorer
Mos : Mosaic

Where a '?' is put in the comparison box, it means that the attribute is claimed to be supported, but on testing, it didn't appear to be so.