the existing data on the receiving side is included in the full-file
checksum verification step, which will cause a file to be resent if the
final verification step fails (rsync uses a normal, non-appending
-bf(--inplace) transfer for the resend).
+bf(--inplace) transfer for the resend). It otherwise has the exact same
+caveats for files that have not grown larger, so don't use this for a
+general copy.
Note: prior to rsync 3.0.0, the bf(--append) option worked like
bf(--append-verify), so if you are interacting with an older rsync (or the