readme

早期freebsd实现

This directory contains an example of a trivial use of Clearinghouse.  The
	retrieve program simply sends a RetrieveAddresses message to a
	known Clearinghouse, and receives as a response the network
	address of that Clearinghouse.

Note that we use a private, abbreviated, copy of the Clearinghouse spec.
The full Clearinghouse.cr (which may be found on /usr/local/lib/courier)
is somewhat large for convenient recompilation.  On the other hand, using
a subset could result in confusion later.