\htmlrule creates a horizontal rule spanning the
full screen width at the current position in the HTML-document.
It has an optional argument that you can use to add additional
attributes to the HTML tag. The optional argument is not evaluated
further, so you should not escape any special characters.
Additional tags are currently only understood by the some browsers, so use the optional argument at your own risk. Here is an example.
\htmlrule[width=70% align=center]This will result in the following rule.
\htmlimage{URL} makes an inline bitmap with the given URL. It takes an optional argument that can be
used to specify additional attributes understood by some HTML browsers. One of the letters "t", "c", "b", "l", or "r" can
be specified as a shortcut for the alignments "top", "center",
"bottom", "left", or "right". So \htmlimage[c]{image.xbm}
includes the image in image.xbm, vertically centered at the
current text position. A more complicated example is (using attributes
that are not in HTML 2):
\htmlimage[align=left width=50 height=75 hspace=3]{image.gif}
~ is quite
common), you have to escape it (as \~{} for the ~).
This is what I use for figures in the Ipe Manual that appear in both the printed document and the HTML-document:
\begin{figure}
\caption{The Ipe window}
\begin{center}
\texorhtml{\Ipe{window.ipe}}{\htmlimage{window.gif}}
\end{center}
\end{figure}
(\Ipe is the command to include "Ipe" figures.)