SGML, on which HTML is based, says that the stuff inside attribute value
literals (i.e. inside the ""'s in ALT="...") doesn't get parsed for tags.
Now we could go ahead and parse it anyway, but that would be a strange
use of the technology.
The functionality that you're asking for has been in the HTML+
proposal for some years now: it's called the FIG element.
Your example would look like:
<FIG SRC="pictures">
<PRE>
._.
/ \
/ \
/-------\
| |_|
| __ |
| <A HREF=door.html>||</A> |
</PRE>
</FIG> My House !
The most recent specification proposal is:
Figures
http://www.w3.org/hypertext/WWW/MarkUp/html3/figures.html
Fri Mar 24 09:56:57 1995
Dan
p.s. Please: everybody read the WWW FAQ[1] and the www-talk/www-html
archives[2] and the recent HTML specs before posting.
[1] http://sunsite.unc.edu/boutell/faq/www_faq.html
[2] http://gummo.stanford.edu/html/hypermail/