+.Pa /etc/services ) .
+When used to specify a
+.Em Sun-RPC
+based service, this field is a valid RPC service name in
+the file
+.Pa /etc/rpc .
+The part on the right of the
+.Dq /
+is the RPC version number. This
+can simply be a single numeric argument or a range of versions.
+A range is bounded by the low version to the high version -
+.Dq rusers/1-3 .
+