"Context Access Control" in vhost security section

[ts77]

Hi there,

I'm trying to implement this configuration:
/ allowed only to subnet 192.168.*
/dir allowed to everyone.

Therefore I've set the vhost to disallow everyone beside the given IP-network and tried to setup a "context" on dir to allow everyone access to this directory.

In this section I read:
"Additional access control can be specified for a context. It is only effective when "Context Access Control" is enabled in virtual host security section."

But I can't find that switch in the security-section of the vhost-configuration.
Am I blind?