The Oracle Solaris 11.1 release includes a new NFS feature called NFS referrals. NFS referrals enable an NFS Version 4 server to point to file systems located on other NFS Version 4 servers as a way of connecting multiple NFS Version 4 servers into a uniform namespace.
NFS Version 2, NFS Version 3, and other types of clients can follow a referral because it appears to them to be a symbolic link.