Group rw on a folder
OK folks. Over nfs4, you can't.
Well, you can but only if your umask is 0002. Unlike the POSIX setfacl, nfs4_setfacl does not override umask. So unless you want to reset your umask to 0002 (you dont!), you can't have group rw on nfs4 by setting the acl. On openSUSE that is where the default umask is 0022. On Ubuntu, the umask is 0002 by default. it's what you get whether you like it or not.
Now, let's see. . .