Other Namespaces
================
Certain other namespaces and associated protocol families are
supported but not documented yet because they are not often used.
`PF_NS' refers to the Xerox Network Software protocols. `PF_ISO' stands
for Open Systems Interconnect. `PF_CCITT' refers to protocols from
CCITT. `socket.h' defines these symbols and others naming protocols
not actually implemented.
`PF_IMPLINK' is used for communicating between hosts and Internet
Message Processors. For information on this and `PF_ROUTE', an
occasionally-used local area routing protocol, see the GNU Hurd Manual
(to appear in the future).