<body> elementThe body element is quite the abused
element:
Of the top twenty most-used attributes on body,
fourteen are purely presentational. Of the remaining six, three are
event handlers; of these, onload is the most common by
a significant margin; then we have onunload and
oncontextmenu, both used on a small fraction of the
pages in the sample. One area of future study would be to see what
these attributes are used for: is onunload used mostly
by Web applications for legitimate purposes, or is it used more by
hostile sites to show pop-unders? Is oncontextmenu
used for good purposes, or to cancel the showing of the context
menu?
The last three attributes are class (probably used
for presentational hooks), id (probably used for
either scripting or CSS signatures), and lang (which
is not used often; it seems it is much more frequently used on the
html element — a good thing, since there it also
catches the metadata in the head).
The presentational attributes provide us with some interesting
insights. For example, the four IE-specific margin attributes
(topmargin, rightmargin,
bottommargin, and leftmargin) are not all
specified the same number of times. People care about the top
margin most of all, then about the left margin, then the right
margin, and then the bottom margin. This is borne out by the
Netscape-specific margin attributes, which are in the same order:
marginheight first, then
marginwidth.
Another insight is that browsers really should stop letting users set default values (as opposed to overrides) for text and background colors: at least half the pages that specify a background color omit to specify a text color, opening up the potential for color clashes. On the subject of colors, we also find that people set the text, unvisited link, and visited link colors much more often than they set the active link color — not that surprising, but we were expecting a much bigger difference between the number of pages that set the visited link color and set the unvisited link color.
One conclusion one can draw from the spread of attributes used
on the body element is that authors don't care about
what the specifications say. Of these top twenty attributes, nine
are completely invalid, and five have been deprecated for nearly
eight years, half the lifetime of the Web so far.