-Note that rsync can only detect hard links if both parts of the link
-are in the list of files being sent.
+When you are updating a non-empty destination, this option only ensures
+that files that are hard-linked together on the source are hard-linked
+together on the destination. It does NOT currently endeavor to break
+already existing hard links on the destination that do not exist between
+the source files. Note, however, that if one or more extra-linked files
+have content changes, they will become unlinked when updated (assuming you
+are not using the bf(--inplace) option).
+
+Note that rsync can only detect hard links between files that are inside
+the transfer set. If rsync updates a file that has extra hard-link
+connections to files outside the transfer, that linkage will be broken. If
+you are tempted to use the bf(--inplace) option to avoid this breakage, be
+very careful that you know how your files are being updated so that you are
+certain that no unintended changes happen due to lingering hard links (and
+see the bf(--inplace) option for more caveats).