caching problems

[gareth]

hey guys, our proxy is caching extremely old copies of the ports index
and portaudit databases from freebsd.org. our admins claim that they
cache the following files i need normally:

http://www.FreeBSD.org/ports/auditfile.tbz
http://www.FreeBSD.org/ports/INDEX-6.bz2

since they have no no-cache pragma directives, and our admins won't
budge on their 'policy'. is the freebsd site breaking standards in
this way? is it feasible to add the directives? if not my solution
is to mirror the files elsewhere and specify this mirror - for
portaudit i see you can specify it in /usr/local/etc/portaudit.conf,
but i can't see where to specify an alternate url for 'portsdb -F'
to use?