In the Solaris OS, named pipes are used as one-way conduits. In Trusted Extensions, named pipes permit write-up operations. The writer runs at a lower label than the reader's dominant label. In Trusted Solaris 8, named pipes were configured by upgrading the label of the FIFO to the reader's label. In Trusted Extensions, named pipes are configured by using read-only lofs mounts of directories in lower-level zones into dominant higher-level zones. The FIFO is created at the label of the zone of the writer. For more information, see the mkfifo(1M) man page.