+### [default_]backup_type
+
+Backup type to use. Default: `rsync`.
+
+- `rsync`: system backup using rsync(1).
+ Use `source_root` to specify the root directory to save.
+
+- `scp`: file backup using scp(1).
+ Use `files` to specify the files to copy.
+
+- `disabled`: job is disabled and will not be run. This becomes accounted as
+ "success" in the summary and exit code of the backup script.
+
+Please note that neither `ssh_args_add`, `rsync_args_add`, `compress`, nor any
+"exclude" parameters are supported when using the "scp" backup type! And There
+"scp" backup type never _deletes_ files from the backup store; so if you reduce
+the list of files to backup, old files will still be kept, because they were
+already saved in an older generation (but no longer updated).
+