Web caching liability

they've been problems for a long time; some of their proxy servers
hold cache data for far too long. i have some web discussion pages
that are effectively useless for aol subscribers because aol even
caches cgi generated stuff with obvious cgi related extensions like
".cgi" and ".pl".

nowhere in the standards is ".pl" recommended to be treated as an
implicit Cache-Control:. if you tag your responses with Cache-Control:
headers that make them do what you want (in this case, make the response
uncacheable) then you won't have the above-described problem.