The following man pages are available:
MagniComp RDist differs greatly from older versions (as distributed with 4.3BSD) in that the client and the server portions are separated into two distinct programs, rdist and rdistd, respectively. The protocol used to communicate between the client and server has also been extensively modified. These changes make providing "builtin" compatibility very difficult. However, backwards compatibility is possible, provided you have a binary or source copy of the old RDist. The way the old RDist started a server RDist is to run "rdist -Server". If the new RDist is run with the "-Server" option, then it will exec a copy of the old RDist (usually /usr/old/rdist or /usr/ucb/oldrdist). In this way, you get compatibility with hosts running the old RDist attempting to RDist to a machine running new RDist. If your host running new RDist wants to RDist to a host running the old RDist, then it must run the old RDist program (/usr/old/rdist or /usr/ucb/oldrdist).
The definition _PATH_OLDRDIST in "config/config.h" controls the location of the old RDist. If this is not defined, or the defined program does not exist at runtime, then RDist will print an error when run with the "-Server" option.