The rsync(1) manpage should document the command line flags --server and --sender, as well as give a "recipe" for unattended mirror scenarios (with SSH public key auth + forced command).
Rsync end users should never need the --server and --sender options; they are used only by the implementation of rsync itself. Thus, I don't think it is necessary to document them in the man page. On the other hand, I don't think it could hurt to mention them in the man page, provided they are marked as "internal" or something so they don't confuse end users.
The SSH forced command thing would do better in a how-to guide than in the man page.
Allright. I would only mention '--server' and '--sender' briefly as internal commands, and will find a section in which I'll describe the mechanism used by rsync to do zero-setup SSH-based synching and how to retrieve the forced command. However, I would not tutor the user on setting up SSH keys etc. in the man page.
The latest manpage mentions the --server and --sender commands near the end in an INTERNAL COMMANDS section (so that normal users will hopefully not confuse --server and --daemon). This new section also mentions the support/rrsync script, which provides an example script for use with a restricted ssh login.