SunOS 3.5 /etc/exports

[George Robbins]

The SunOS 3.5 man page doesn't show any option in the /etc/exports file
for exporting a file read only.  Is this really the case or is it a
documentation error?  Is the capability implemented in some other fashion?

We have an Ultrix system on the ethernet that allows random users to mount
filesystems at will, which defeats using mount -r type fstab entries on
that system to make access to the NFS filesystem readonly.  This causes a
conflict in our desire to have various filesystems writable only by their
"owners" and read-only otherwise...