I was trying to do some mod_rewrite things in .htaccess that involved a RewriteRule with [P] -- but DH didn't seem to like that. (The same .htaccess works fine for a site hosted by a different provider.) Does anyone know if DH prohibits [P]? I asked support, and they said they weren't aware of anything.
(In particular, I was doing:
RewriteRule ^(.*)$ http://bar.com/$1 [P]
...which is straight out of the mod_rewrite guide, and does work fine for me on other systems.)