used instead of the new format.)
``max-ixfr-ratio``
- This sets the size threshold (expressed as a percentage of the size of the full
- zone) beyond which ``named`` chooses to use an AXFR response rather than
- IXFR when answering zone transfer requests. See
+ This sets the size threshold (expressed as a percentage of the size
+ of the full zone) beyond which ``named`` chooses to use an AXFR
+ response rather than IXFR when answering zone transfer requests. See
:ref:`incremental_zone_transfers`.
+ The minimum value is ``1%``. The keyword ``unlimited`` disables ratio
+ checking and allows IXFRs of any size. The default is ``100%``.
+
``new-zones-directory``
This specifies the directory in which to store the configuration
parameters for zones added via ``rndc addzone``. By default, this is