I really wish RH would hop on the /srv bus. The broad distinction is fairly easy to grasp: /var for variable data of general interest to the machine, /srv for stuff related to a specific service. In general, /var is machine-generated, /srv is person-generated.
If you maintain it with $EDITOR and it's available with $DAEMON, it goes in /srv. (How's that for a stunningly broad generalization? :-)
It's not just RH/CentOS that are guilty. Last time I checked Debian does this as well.
On my webserver I've just grown used to making up my own /srv/www entry and symlinking /var/www to /srv/www so the system doesn't complain when apache & related apps get updated.