+dit(bf(--append)) This causes rsync to update a file by appending data onto
+the end of the file, which presumes that the data that already exists on
+the receiving side is identical with the start of the file on the sending
+side. If that is not true, the file will fail the checksum test, and the
+resend will do a normal bf(--inplace) update to correct the mismatch. Any
+file on the receiving side that is longer than a file on the sending side
+is skipped. Implies bf(--inplace).
+