I just happened to notice that the self, next and last links in the Atom feed [1] are pointing at the wrong place: <feed xmlns="http://www.w3.org/2005/Atom"> <title>Library of Congress Subject Headings</title> <link href="http://id.loc.gov/subjects/feed/1" rel="self"/> <link href="http://id.loc.gov/subjects/feed/2" rel="next"/> <link href="http://id.loc.gov/subjects/feed/4117" rel="last"/> <id>info:lc/authorities/subjects/feed</id> ... </feed> should instead look like: <feed xmlns="http://www.w3.org/2005/Atom"> <title>Library of Congress Subject Headings</title> <link href="http://id.loc.gov/authorities/subjects/feed/1" rel="self"/> <link href="http://id.loc.gov/authorities/subjects/feed/2" rel="next"/> <link href="http://id.loc.gov/authorities/subjects/feed/4117" rel="last"/> <id>info:lc/authorities/subjects/feed</id> ... </feed> The same seems to be the case for the LCNAF feed [2] as well. Since I'm on the subject, I've noticed that digging back in time seems to take longer the further you go. ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/501/ > /dev/null real 0m3.193s user 0m0.004s sys 0m0.008s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/1001/ > /dev/null real 0m12.031s user 0m0.008s sys 0m0.004s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/1501/ > /dev/null real 0m15.623s user 0m0.004s sys 0m0.008s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/2001/ > /dev/null real 0m22.023s user 0m0.012s sys 0m0.004s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/2501/ > /dev/null real 0m24.492s user 0m0.004s sys 0m0.008s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/3001/ > /dev/null real 0m27.716s user 0m0.008s sys 0m0.008s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/3501/ > /dev/null real 0m46.800s user 0m0.008s sys 0m0.008s ed@taylor:~$ time curl --silent http://id.loc.gov/authorities/subjects/feed/4001/ |less real 0m1.225s user 0m0.008s sys 0m0.012s I'm not sure if some optimizations can be made there. I guess the silver lining is that Varnish appears to be caching the result, so it's just the first person to request the URL that has to pay the price. //Ed [1] http://id.loc.gov/authorities/subjects/feed/1 [2] http://id.loc.gov/authorities/names/feed/1