--- /dev/null
+.. Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+..
+.. SPDX-License-Identifier: MPL-2.0
+..
+.. This Source Code Form is subject to the terms of the Mozilla Public
+.. License, v. 2.0. If a copy of the MPL was not distributed with this
+.. file, you can obtain one at https://mozilla.org/MPL/2.0/.
+..
+.. See the COPYRIGHT file distributed with this work for additional
+.. information regarding copyright ownership.
+
+Notes for BIND 9.21.18
+----------------------
+
+Feature Changes
+~~~~~~~~~~~~~~~
+
+- Update requirements for system test suite.
+
+ Python 3.10 or newer is now required for running the system test
+ suite. The required python packages and their version requirements are
+ now tracked in `bin/tests/system/requirements.txt`.
+
+ Support for pytest 9.0.0 has been added its minimum supported version
+ has been raised to 7.0.0. The minimum supported dnspython version has
+ been raised to 2.3.0. :gl:`#5690` :gl:`#5614`
+
+- Lowercase the NSEC next owner name when signing.
+
+ When building the NSEC rdata, lowercase the next owner name before
+ storing it in the Next Domain Name Field.
+
+ Note that this is not required according to RFC 6840, but since there
+ is inconsistency in the documents over time, having uppercase next
+ owner names in the NSEC records may cause validation failures if
+ validators are not following RFC 6840. :gl:`#5702`
+
+- Enable minimal ANY answers by default.
+
+ ANY queries are widely abused by attackers doing reflection attacks as
+ they return the largest answers. Enable minimal ANY answers by
+ default to reduce the attack surface of the DNS servers. :gl:`#5723`
+
+Bug Fixes
+~~~~~~~~~
+
+- Make catalog zone names and member zones' entry names
+ case-insensitive.
+
+ Previously, the catalog zone names and their member zones' entry names
+ were unintentionally case-sensitive. This has been fixed. :gl:`#5693`
+
+- Fix brid and hhit implementation.
+
+ Fix bugs in BRID and HHIT implementation and enable the unit tests.
+ :gl:`#5710`
+
+- DSYNC record incorrectly used two octets for the Scheme Field.
+
+ When creating the `DSYNC` record from a structure, `uint16_tobuffer`
+ was used instead of `uint8_tobuffer` when adding the scheme, causing a
+ `DSYNC` record that was one octet too long. This has been fixed.
+ :gl:`#5711`
+
+- Fix a possible issue with reponse policy zones and catalog zones.
+
+ If a response policy zone (RPZ) or a catalog zone contained an
+ `$INCLUDE` directive, then manually reloading that zone could fail to
+ process the changes in the response policy or in the catalog,
+ respectively. This has been fixed. :gl:`#5714`
+
+