I suppose they use User-Agent sniffing, which is obviously not very robust. That said, something like the rule below should work (mod_gzip/Apache 1.x): mod

I suppose they use User-Agent sniffing, which is obviously not very robust. That said, something like the rule below should work (mod_gzip/Apache 1.x): mod_gzip_item_include reqheader "User-agent: .*MSIE 6.0.*" Mind you, this has not been tested, interacts badly with proxies, and is based on a pretty broken idea in the first place. On the other hand, almost every modern browser supports gzip, so it's not clear how much it would hurt.