I currently have several conference rooms set up to be able to directly

book the room by inviting it as a resource. This is working ok, but
some users will open the calendar by "Open a Shared Calendar"
selecting the conference room and directly reserving a time on the
room's calendar. All the users have Author privileges to the
resource calendar so that we can directly book by inviting the room as
a resource. Is there any way to block users from opening a resource
calendar
directly and reserving the resource or set the resource calendar to
only accept meeting requests?
We're running Outlook 2003 SP2 and Exchange 2003 SP2.