[Zope] Fw: Enrollment Error (fwd)

When executing a method throught the web, we have seen the following error message...

Site Error An error was encountered while publishing this resource.

Error Type: IOError Error Value: [Errno 13] Permission denied: '<<<some directory path>>>/var/Data.fs.index.index_tmp'

which googling suggests is due to the protections of the var directory not having public write permissions set. My configuration vis a vis permissions is right out of the book drwxr-xr-t 2 root root 4096 Oct 27 17:39 var with zope running as a local user ( -u zope ). The question, then, is "What should the permissions on var be?".