diff --git a/doc/release-notes.md b/doc/release-notes.md
index 2d833fe42..5db8dfb03 100644
--- a/doc/release-notes.md
+++ b/doc/release-notes.md
@@ -1,31 +1,70 @@
 Bitcoin ABC version 0.21.9 is now available from:
 
   <https://download.bitcoinabc.org/0.21.9/>
 
 This release includes the following features and fixes:
 - Improve management of maxfee by the wallet.
 
+
 Wallet changes
 --------------
 When creating a transaction with a fee above `-maxtxfee` (default 0.1 BCH),
 the RPC commands `walletcreatefundedpsbt` and  `fundrawtransaction` will now fail
 instead of rounding down the fee. Beware that the `feeRate` argument is specified
 in BCH per kilobyte, not satoshi per byte.
 
+
+Coin selection
+--------------
+
+### Reuse Avoidance
+
+A new wallet flag `avoid_reuse` has been added (default off). When enabled,
+a wallet will distinguish between used and unused addresses, and default to not
+use the former in coin selection.
+
+(Note: rescanning the blockchain is required, to correctly mark previously
+used destinations.)
+
+Together with "avoid partial spends" (present as of Bitcoin ABC v0.19.9), this
+addresses a serious privacy issue where a malicious user can track spends by
+peppering a previously paid to address with near-dust outputs, which would then
+be inadvertently included in future payments.
+
+
 New RPCs
 --------
 
 - `getbalances` returns an object with all balances (`mine`,
   `untrusted_pending` and `immature`). Please refer to the RPC help of
   `getbalances` for details. The new RPC is intended to replace
   `getunconfirmedbalance` and the balance fields in `getwalletinfo`, as well as
   `getbalance`. The old calls may be removed in a future version.
 
+- A new `setwalletflag` RPC sets/unsets flags for an existing wallet.
+
+
 RPC changes
 -----------
+
 The `getblockstats` RPC is faster for fee calculation by using BlockUndo data. Also, `-txindex` is no longer required and `getblockstats` works for all non-pruned blocks.
 
+Several RPCs have been updated to include an "avoid_reuse" flag, used to control
+whether already used addresses should be left out or included in the operation.
+These include:
+
+- createwallet
+- getbalance
+- sendtoaddress
+
+In addition, `sendtoaddress` has been changed to enable `-avoidpartialspends` when
+`avoid_reuse` is enabled.
+
+The listunspent RPC has also been updated to now include a "reused" bool, for nodes
+with "avoid_reuse" enabled.
+
+
 Miscellaneous RPC changes
 ------------
 
 - `createwallet` can now create encrypted wallets if a non-empty passphrase is specified.